Silicon based batteries:FAST literature review

Silicon Carbide Nanoparticles as a Mechanical Boosting Agent in Material Extrusion 3D-Printed Polycarbonate^[1][edit | edit source]

• DIW of SiO at C/graphite.

3D printer info and variables	DIW	nozzle: ID 260-610 micro	Thickness: 418 (2 layers), 692 (3), 806 (4), 1050 micrometer	Mass loading: 39.2, 60.9, 84.2 mg/cm2	weight ratio of SiO/graphite, MWCNTs, and binders: 70/20/10	extrusion speed: 40%	scanning velocity: 8 mm/s	layer thickness: 0.2 mm	269 micrometer line width by 24G nozzle tip, thickness 418 micrometer	Comb-like design
Equipment	Ultrasonic	Magnetic stir	vacuum
Material	Current collector: foam Al and Cu	electrolyte: 1.0 M LiPF6 EC: EMC. DEC ¼ 1:1:1 + 2% FEC	cathode: LFP
Steps	Ink preparation	3D printing	vacuum Freeze-drying
TESTS	half cell electrochemical (Li-foil)	Full cell with LFP	apparent viscosity/ shear rate for ink	rate performance (specific capacity/cycle number)	Areal capacity	impedance spectroscopy	charge/discharge	Ragone plot between areal energy density and power density	storage modulus and loss modulus/ shear stress for ink	SEM	EDS	mercury intrusion porosimetry (porosity, pore size, and distribution)
Results	Areal capacity: 17.9, 26.7, 32.2 mAh /cm2 (respectively with thickness (mass loading))	Solid content of the ink: 40% is preferable	Porosity: 50-200 nm (nano scale)	Porosity: 1-3 micrometer (micro scale)	Porosity: 100-300 micrometer (macro scale)	20% of MWCNT is prefarable	269 micrometer line width by 24G nozzle tip, thickness 418 micrometer are preferable (276 mAh/g @ 3 C specific capacity)	Mass loading of 806 thickness which is 84.3 mg/cm2 is preferred

A 3D-Printed, Freestanding Carbon Lattice for Sodium Ion Batteries^[2][edit | edit source]

• Na battery fabrication with SLA
• pyrolysis
• SLA of hard carbon microlattice then pyrolysis---> Increasing the mass loading --> increasing the energy density and compacting the battery size

3D printer info and variables	mass loading 98 mg cm−2	beam lengths and widths: 400-133	x and y pixel resolution of 50 µm	50 µm thick pattern layer	lattice architecture	70% in x -75% in y shrinkage after pyrolysis	(x,y) = (119.9, 32.8) for 400-133 after the pyrolysis	resolution= 50 µm	UV exposure time= 35 s for the first layer, 2s for the rest	retraction velocity of the platform= 80 mm/ min
Design	lattice architecture
Equipment	LCD-SLA 3D printer	fused quartz tube
Material	Photocurable resin (phenolic epoxy resin and methacrylate monomer)	2-propanol	cathode: Na metal foil	electrolyte: 1.0 m NaPF6 in PC	separator: glass fiber filter	binder: PTFE (or PVDF, but it is reported that PTFE is better)
Steps	material preparation	3D print	immerse the electrode in 2-propanol for 3h	dry in ambient condition	first pyrolyzed at 400 for 4h, then 1000 for 4h	2032 coin-type cell
TESTS	Raman spectrum	energy-dispersive X-ray spectroscopy	Charge/ discharge	rate performances	SEM	XRD	calculation diffusion coefficient
Results	extraordinary high areal capacity of 21.3 mAh cm−2 at 98 mg/ cm^2	low crystallinity so we have hard carbon	70% in x -75% in y shrinkage after pyrolysis	bigger graphite that has more space to store Na ions	Coulombic efficiency of 80% in first cycle	increased capacity as the micro structure becomes finer	the overpotential reduces as the micro structure becomes finer	the rate performance improved as the micro structure becomes finer	better capacity as the micro structure becomes finer	the beam width should be as fine as possible	the beam density can be as dense as possible	stable over long term cycling	the total capacity just decreased at the 2nd cycle and no additional lost to 100th cycle	the more mass loading, the more areal capacity	the Na efficiently utilized the entire mass regardless the thickness	increasing the mass loading in conventional method, reduces the areal capacity	shortening the diffusion pathway

3D printed silicon-few layer graphene anode for advanced Li-ion batteries^[3][edit | edit source]

• 3D printing of batteries -->controlling the design & increasing the energy storage
• FDM printing of Si-based anode using PLA as matrix, carbon black-doped polypyrrole and graphene as conductive and Si nano particles as active materials.
• pores inside the 3D printed anodes --> helps the Si to accommodate the volume change during lithiation and delithiation.

3D printer info and variables	FDM	nozzle: 0.4 mm	Nozzle and bed temp: 210- 60 degrees	printing speed: 40 mm / s	Infill density: 100%	Design: electrode with diameter 1 cm, thickness 0.2 mm
Equipment	Ultra Centrifugal Mill	Mechanical stirrer	Planetary mixer	A twin-screw extruder
Material	Current collector:	electrolyte: Solvionic, 1 M LiPF6 in dimethyl carbonate, DMC : ethylene carbonate, EC 1 : 1 v/v	counter electrode: Li metal	Si nanoparticles (100 nm)	Graphene powder	PLA pellets	cunductive: Carbon black-doped PPy	Separator: Whatman borosilicate
Steps	powdering PLA using Ultra Centrifugal Mill	Dry at 85 degree one night	planetary mixing of PLA, Si, Graphene and carbon black (70wt%, 16, 3, 11)	Extrude a 1.75 mm filament with 175-205 degrees temp	print
TESTS	TEM	SEM	EDX	TGA	tensile tests (by Instron Dual Column Tabletop Universal Testing System)	EIS in 0.02 V voltage amplitude, 0.01- 200 kHz frequency	XRD	Raman spectra	electrical conductivity (Loresta-GX MCP-T700)	Biologic battery tester (0.1-2 V), 20-50 mA/g, CV scan rate: 0.1 mV/s	Specific capacity	Charge/discharge	Rate capability	Long-term cyclic performance and coulombic efficiency	Nyquist plots	cyclic voltammetry (CV)	Gravimetric and volumetric capacities
Results	Capacity retention: 96% after 350 cycles	specific capacity: 345 mAh / g at 20 mA/g current density

DLP printing of a flexible micropattern Si/PEDOT:PSS/PEG electrode for lithium-ion batteries^[4][edit | edit source]

(great source to link other sources for the introduction)

• free standing 3D printed Si/ PEDOT:PSS/ PEG electrode for Li-ion batteries with DLP.
• The purpose: maximizing the energy storage and minimizing battery weight
• The results: structural integrity and flexibility
• Li ion batteries Advantages: high efficiency, rechargeability, high energy density, small weight, portability
• 3D printing of battery Advantages: complex shapes, control the geometry and architecture--> the same properties inside the architecture like the surface
• SiC Advantages: ultrahigh theoretical capacity and low potential for Li uptake.
• SiC Disadvantages: changes in volume during charging and discharging
  • Pulverizing the Si -->form a solid layer at the electrode/ electrolyte interface---> Li dendrites because of the in-homogeneous deposition of Li ions.---> penetrate to the seperator---> short out the cell---> safty issues.
  • creating SEI --> electrolyte over-consumption ---> low CE & poor cycling stability.

3D printer info and variables	DLP printing	Distance 0.04 mm between patterned lines	the fisrt electrode diameter: 15.5 mm after drying: 14 mm	30% of Si load	honeycomb design	width of line is 50 mm	200 micrometer laser spot diameter	UV wavelength 375 nm	resolution 75 micrometer	the active material loading in the electrode is 4.2 mg/cm^2
Equipment
Material	solid PEDOT:PSS	Si NPs	PEG	Li current collector
Steps	7 mL of water and EG (8:1) + 70 mg of PEDOT:PSS+0.3 g Si NPs	Sinication of the solvent for 20 min	Add BAPO and photoinitiator	Stir over night	PEF/Si/PEDOT:PSS (60/20/5)	3D print	Dry in a vacuum at 80 degrees for 8 hours	Preparing conventional electrode for comparison (70 Si, 10 carboxymethyl cellulose as binder, 20 acetylene black as conductive agent)	doctor blade the conventional electrode on the Cu foil and dry at 80 degrees) with 20 micrometer thickness and the actice material is 2.2 mg/cm^2
TESTS	SEM	Viscosity	DSC-TGA	Charge/ discharge	Nyquist plots
Results	specific discharge capacity of 1658.4 mA h g-1	capacity fade of 0.3% per cycle at 800 mA/g current density after 125 cycles	load of 4.2 mg cm-2.	300 micrometer distance from SI nano particles	From SEM: dispersion of Si, and the position that they are on the surface	From TG: 3 peaks: PEG desorption, PEDOT:PSS thermal decomposition, Si oxidation	charge (discharge) capacity of 1539 (1783) mA h/ g	improved CE of 86.3%	no reduction of charge/ discharge after 125 cycles	reversible capacity of 1105 mA h g-1

Synthesis of SiC Resin for 3D Printing of SiC Ceramics by Digital Light Processing^[5][edit | edit source]

(for choosing photoinitiator)

• SiC resin + Tethon's high load Genesis & different loads: 10, 20, and 30 % .
• the low viscosity --> DLP print of further than 30 percent (even 50 percent)

3D-printed electrically conductive silicon carbide^[6][edit | edit source]

(for choosing photoinitiator and dispersant)

• vat photopolymerization -->fabricate high electrical conductive
• low thermal conductive, and high thermal stable SiC.

3D printer info and variables	vat photopolymerization	layer thickness 0.05 mm
Equipment	sonicator
Material	porous silica	Poly (ethylene glycol) diacrylate (PEGDA)	graphene	Photoinitiator: Phenylbis (2, 4, 6-trimethylbenzoyl) phosphine oxide	Light absorber: 2-Nitrophenyl Phenyl Sulfide	Dispersing agent: Darvan 811
Steps	Ink	3D printing	heat treatment	CHaracterization
TESTS	SEM	TEM	XRD	Barrett-Joyner-Halenda (BJH)	stress-strain behavior	current-voltage	TGA
Results	amorphous below 1400 pyrolysis temp

Additive manufacturing of SiBCN/Si3N4w composites from preceramic polymers by digital light processing^[7][edit | edit source]

(for choosing photoinitiator)

Material	Preceramic polymer: polyborosilazane (PBSZ)	photo polymerization reactive: trimethylolpropane triacrylate (TMPTA),	Photoinitiator: IRGACURE 819	dispersant: ??? (not mentioned what)	Si3N4 whiskers

3D printing of multicolor luminescent glass^[8][edit | edit source]

(for choosing photoinitiator)

• Steriolithography of luminescent transparent glass
• After printing-->immersing the part in ethanol solutions for 15 min -->drying at 60 degrees, sintering at 1250 for 3h.

Material

Preceramic polymer: polyborosilazane (PBSZ)

photosensitive monomer: 28.1 wt% HEMA (2-Hydroxyethyl methacrylate)

plasticizer: 14.5 wt% diethylphthalate

crosslink agent: 3.7 wt% PEGDA 200

53.7 wt% amorphous silica

photo initiator: 0.4 wt% DMPA

poly(ethylene glycol) diacrylate 200 (PEGDA 200)

diethyl phthalate (99.5%)

4-methoxyphenol (MEHQ, 99%)

2,2-dimethoxy-2-phenylacetophenone (DMPA, 99%)

photo absorber: 0.2 wt% Tinuvin 1130

Thermo-mechanical and swelling properties of three-dimensional-printed poly (ethylene glycol) diacrylate/silica nanocomposites^[9][edit | edit source]

(for choosing photoinitiator)

Material	main resin: poly (ethylene glycol) diacrylate	photoinitiator PL-TPO 2,4,6-trimethylbenzoyldiphenylphosphine oxide
PEGA+ photoinitiator+ SiO2	ultrasonicated for 30 min

Synthesis and characterization of hybrid silica/PMMA nanoparticles and their use as filler in dental composites^[10][edit | edit source]

(For choosing dispersant)

• CTAB: dispersion material for dispersing Si in PMMA (ionic interaction between positively charged CTAB and negatively charged Si particles ---> forming a hydrophobic interphase --> improving the dispersion of nanoparticles in water & diffusing MMA monomers into the hydrophobic layer--> form a shell.
• adding Si to aqueous CTAB at 2% --> stirring for 2 h at 50 degrees -->adding MMA monomer --> polymerizing---> result: PMMA

Preparation of micron Si@C anodes for lithium ion battery by recycling the lamellar submicron silicon in the kerf slurry waste from photovoltaic industry^[11][edit | edit source]

• kerf slurry waste (Si) --> down to sub micrometer size through ball milling
• reacting with glucose and form micron SiC --> Si in the core & glucose around Si
  • storing Li ions inside si
  • damping the Si expansion & electrical conductivity by carbon
• Battery assembly: 250 g of SiC & Super P & PAA (8:1:1) in 1 mL distilled water---> casting in 100 micrometer thickness---> dry in vacuum at 70 degrees for 10h--> cooled at room temp.
  • CR2032 coin cell
  • Battery components: 1) Celgard 2500: separator, 2) was LB-044 consisted of an organic solution of 1.0 M LiPF6 in ethylene carbonate (EC)/dimethyl carbonate (DMC)/diethyl carbonate (DEC) (1:1:1 by volume) with 10.0% fluoroethylene carbonate (FEC) and 2.0% vinylene carbonate (VC): electrolyte, 3) metallic lithium: counter electrode
• acceptable Si size for LIB: 50-100 nm (reference 52)
• Considering each dimension separately -->the particle with nm size in one direction---> the volume expansion in that direction
• from FT-IR: Si-C bond

Equipment	ball mill	autoclave
Material	2.2 g of 500 nm Si particles	4.5 g glucose	0.9 g Ni nitrate hexahydrate (catalyst)	50 mL distilled water
Steps	ball milling the kerf slurry waste with 3-mm ball size	Mixing powders with water	heat the mixture in oil bath in autoclave in 190 degrees for 6 h	further carbonize the mixture at 700 degrees under N2 for 3h	adding graphene during preparation to increase the conductivity
TESTS	Zetasizer Nano ZS (for particle size)	SEM	FESEM	EDS	XRD	FT-IR	Raman spectra	XPS	galvanostatic charge/discharge (battery test system)	electrochemical impedance spectroscopy (electrochemical workstation)
Results	specific discharge capacity is 3210.5 mAh/g for 0.1C	reversible capacity 1788.9 mAh/g after 200 cycles

High-performance LiFePO4 and SiO@C/graphite interdigitated full lithium-ion battery fabricated via low temperature direct write 3D printing^[12][edit | edit source]

(great source for analysis)

• Direct ink printing of SiO@C/ graphite comb-like structure.
• The solid content: 40%
• The weight ratio of SiO/graphite, CNT, and binder: 70:20:10.
• SEM images: the printed parts line width & thickness --> more than the aimed print --> material expansion after flowing out of the nozzle & large initial gap between nozzle tip and the bed at the beginning of the printing process.

3D printer info and variables	direct writing 3D printing	Comb-like design	-20 degrees printing temp	418, 692, 806 micrometer thickness	39.2, 60.9, and 84.3 mg/ cm2 mass loading	nozzle tip 260-610 micrometer	weight ratio (70:20:10 for SiO/graphite+ CNT+binder)	best solid content is 40%	extrusion speed 15 percent	scanning velocity 8 mm/s	layer thickness 0.2 mm
Equipment	ultrasonic
Material	LFP cathode	SiO@C anode	CNT (conductive)	styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) (binder)	1,4 dioxane and de-ionized water (solvent) (high freezing temp)	Al and Cu current collector	Li-foil counter electrode	lithium hexafluorophosphate (LiPF6)-ethylene carbonate (EC), methyl ethyl carbonate and dimethyl carbonate plus a 2% solution offluoroethylene carbonate (FEC) (1.0 M LiPF6 EC: EMC. DEC ¼ 1:1:1 þ 2% FEC) (electrolyte)
Steps	CNT in solvent (ultrasonic for 2h)	Add CMC (stir magnetically for 12 h)	Add SiO@C/graphite powder (stir mechanically in vacuum for 4h)	Add SBR (stir mechanically for 4h in vacuum)	vacuum filtering	3D print	freeze dry for 12 h
TESTS	coin like half cell for SiO@C/graphite	coin full cell for SiO@C/ Graphite and LFP	rheological properties	optical microscopy	SEM	EDS	porosimetery	Charge/ discharge	rate performance	cycling performance	cyclic voltametry	impedance spectroscopy
Results	17.9, 26.7 and 33.2 mAh/cm2 at 0.3C areal capacity (based on thickness)	porosity is 60%	The best result is from 418 thickness and 269 line width which has 276 mAh/g @ 3C specific capacity

Ultrastable Silicon Anode by ThreeDimensional Nanoarchitecture Design^[13][edit | edit source]

• Solving the issues of fracture, conductivity, and instability of SEI of Si anode.
• Slurry coating: LiFePO4 powder, carbon black and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1
• prototype full cells: assembled by paring NG@Si-30@HSi anodes with LiFePO4 cathodes--> commercial viability of the hybrid Si anodes.
• Before assembling full cells--> stabilizing the N-G@Si-30@HSi anodes in the half cells for 20 cycles --> eliminate the irreversiblity.

Equipment
Material	attaching Synthesis of N-doped Graphene@Si@Hybrid Silicate to Al rod with conductive silver epoxy (working electrode)	scattered Li metal on a tungstan rod as reference and counter electrode	Whatman glass fiber as the separator	LiPF6 dissolved in ethyl carbonate and diethyl carbonate (1:1 in volume) with 5 wt % fluoroethylene carbonate additive (electrolyte)
Steps	add N-doped graphene on Ni substrate using CVD	loading Si on graphene using RF magnetron	Synthesis of N-doped Graphene@Si@Hybrid Silicate by vapor deposition method
TESTS	Phase	EDS	SEM	TEM	XPS	Raman	galvanostatic cycling of CR2032-type coin cells (Hokuto battery testing system)	electrochemical impedance measurement	R2032-type symmetric cells
Results

Drop‑on‑demand 3D‑printed silicon‑based anodes for lithium‑ion batteries^[14][edit | edit source]

(just in case, ink preparation is provided)

• coating carbon on SiNi nanoparticles.
• the ratio of SiNi/sucrose/ CNT: 77.4/22.1/0.5 %wt
• the CNT: suspension of 0.2% CNT & 0.4% PVP in water
• LiPAA: dissolution of PAA in water --> heat to 60 for 3 days --> stir with lithium hydroxide (1:1 molar of carboxyl to hydroxide)
• CELL ASSEMBLY:
  • drying printed anodes under vacuum at 50 degrees for 12 h and at 100 degrees for 2h
  • assemble the CR2032 coin-cell type setup.
• anode detachement from the Cu when drying.
• NaPAA: water absorbance --> shrinkage when drying

3D printer info and variables	strips geometry and cast-like geometry	600-800 micrometer distance between printed lines
Equipment	pyrolyze furnace	mortar and pestle	polypropylene (Celgard 2400) as seperator	15-mm lithium metal discs as counter electrode	0.85 M lithium hexafluorophosphate in a mixture of ethylene carbonate, diethyl carbonate (1:1) with added vinylene carbonate (2%) (Solvionic), mixed with 15% fluoroethylene carbonate (SolvayFluor) as electrolyte	Cu current collector
Material	Si	NiNPs	CNT	sucrose	raphite as active material	LiPAA in water as binder
Steps	Mix Si and Ni (1:0.3)	dry	heat treat at 900 for 2 h	add CNT and sucrose in water	dry	pyrolyze at 1000 degrees for 1h	grind manually	add to ink slurry	add graphite+ LiPAA (the final ratio is 80:10:10)
TESTS	battery cycling	EIS	SEM	EDS	TGA
Results

3D Printed Multilayer Graphite@SiO Structural Anode for High-Loading Lithium-Ion Battery (good good good)^[15][edit | edit source]

preparing GS ink and Gt ink-based electrode--> Direct ink printing. (good for Victor's printer)

• The ratio of Gt and SiO: 4:1.
• active material: mixed with acetylene black and PVDF (7:2:1) in NMP.
• two nozzles to print Gt and GS layer after layer.
• The assembled full cell with 3D printed lithium nickel manganese oxide (LiNi0.5 Mn1.5O4, LNMO) cathode

Nano-silicon @ soft carbon embedded in graphene scaffold: High-performance 3D free-standing anode for lithium-ion batteries^[16][edit | edit source]

(This introduces the surfactent for Si)

• making an anode with SiNP in soft carbon and graphene scafold.
• soft carbon: decrease volume expansion & prevents SEI formation
• Soft carbon: crystalline and amorphous regions for Li ion diffusion.
• The SiNP: evenly distributed in graphene --> eliminating the collision of SiNP--> electronic conductivity, Li ion diffusion, and high SiNP content.
• Mass ratio: SNPs/ graphene/SBL 6:3:1
• GSCS: SNPs/ graphene/SBL then heat treatment
• Si/G: similar to GSCS without heat treatment
• PDDA: as cationic polyelectrolyte--> large positive charge on the SNPs surface
• SBR: polymer containing H and C --> C without impurity.

Equipment
Material	SiNP	Diethylene glycol diacrylate phthalate (PDDA) (it activates the Si particles)	Styrene-butadiene latex (SBL)	Graphene
Steps	1 g SNP in 10 mL PDDA aquas solution and stir it for 4h, then wash it with DI water, then dry it in vacuum at 40 degrees for 24h	0.3 g graphene and 0.7 g of the prepared SiNPin 100 mL DI water, stir for 4h at 40 degrees, filter and dry at 40 degrees in vecuum	0.1 g of the previous into 4 g SBL, ultrasonic for 30 min, pour in glass mould, soft-bake at 40 degrees to make rubber	treat the mixture at 500 degrees in Ar gas for 4h
TESTS	SEM	TEM	XRD	Raman	XPS	potential analysis	FT-IR	TG	DSC	Digital multimeter (we use it when the materials are punched into 14.2 mm diameter electrode)	tensile test	galvanostatic discharge/charge with battery testing syste	EIS
Results

Flexible free-standing graphene-silicon composite film for lithium-ion batteries^[17][edit | edit source]

• synthesizing graphene-Si for Li batteries --> in-situ chemical method with graphite oxide.
• previous works: highest battery performance --> 45% Si and 55% C.
• free standing composite film--> lower conductivity rather than metal substrate--> less Si in this work.
• the graphene in the composite:
  • preventing Si particles from agglomeration
  • elastic matrix to accommodate mechanical stress
  • keep the structural integrity.
• voids to buffer the volume change --> the electrode is not pulverized (we still have expansion)
• graphene -->lowering the internal resistance for both e and ions (this makes the de alloying easier)--> easier ion transformation

Equipment
Material	Si	GO
Steps	5 mg SiNP into 200 mL GO dispersion with 200 mg NaOH and 290 mg pyrenebutyric acid	2h ultrasonication	reducing (graphite to graphene) with 1 mL hydrazine monohydrate at 80 degrees with stirring for 24h	cool to room temp	PVDF in 50:50 DI water to ethanol for 30 min	pssing the GO/Si from VDF filter in a filtration cell to produce free-standing Graphene-Si	washing with DI water	remove from PVDF after drying in vacuum at 60 overnight	heat treat at 500 for 10h in Ar to remove -H and -OH
TESTS	FE-SEM	TEM	XRD	EDS	TGA	CR 2032 coin (Li foil counter and reference electrode, 1 MLiPF6 in a 50:50 (v/v) mixture ofethylene carbonate and dimethyl carbonate as electrolyte)	charge/discharge	raman
Results

Waste glass microfiber filter-derived fabrication of fibrous yolk-shell structured silicon/carbon composite freestanding electrodes for lithium-ion battery anodes^[18][edit | edit source]

(introduces a way to reduce the waste (SiO2) to Si)

• the waste glass fibers: amorphous with a wide range diameter ranging from nm to micrometers
• deep MgR: for extracting Si -->turns the waster to Mg2Si and MgO.
• the oxidation: Mg2Si to Si and MgO.
• HSl washing -->remove the MgO
• battery test:
  • the samples: active materials (80%)
  • ketjen black: conductive material (10%)
  • sodium carboxymethyl cellulose (10%) in DIW.
  • slip-casting the materials on the Cu foil and punching
• different electrodes with different time of carbonization: 30 min carbonization--> the optimum one.

Equipment	galvanostatic cycler	Swageloktype half cells	electrical oven
Material	waste glass	Magnesium powder	ketjen black	sodium carboxymethyl cellulose	copper foil	counter electrode: Li metal foil	seperator: GF (GF/F, Whatman)	1.0 M LiPF6 electrolyte in ethylene carbonate/dimethyl carbonate (EC/DMC; 1:1 v/v, Sigma-Aldrich) with 10 vol% fluoro-ethylene carbonate (Soulbrain) additive	HCl	DI water
Steps	mixing and annealing 0.16 g of glass with 0.32 g Mg powder the anneal was for 10 h at 600 degrees in Ar	we get Mg2Si after this step	heat treat the mixture for 5h at 600 degrees to change the structure to MgO and Si	immerse the mixture in HCl for 1h to remove the MgO	wash the precipitance wtith DI water	freeze the sample under -30 degrees and dry uder vacuum for 12 h	punch the material into 1 cm diameter disks	using acetone, the Si is coated with carbon through CVD	immerse the disks into HCl and same washing prodess	dry the samples in electrical oven at 90 degrees for 12 h
TESTS	FE-SEM	XRF	XRD	TEM	elemental analysis	Brunauer-Emmett-Teller analysis
Results

The preparation of SiC ceramic photosensitive slurry for rapid stereolithography**^[19][edit | edit source]

(For choosing the polymer resin, photoinitiator and dispersant)

• SiC powder: high optical absorbance & refractive index --> reducing the penetration depth and curing thickness
• print SiC with less solid content--> still shrinkage & deformation after debonding
• acrylate monomer: high curing rate --> 40% of solid content--> printable layer thickness: 70 um --> npt good for big parts
• graded silica --> improve the curing thickness & rheological & settling performance
• using LSI method to fabricate SiC
• slurry: high solid content, low viscosity, low sedimentation rate and high curing thickness
• solving shrinkage problem after sintering: as high solid content as possible
• final SiC particle size: 30 um
• mixing: mechanically
• average particle size, volume fraction particles, spacing between particles, and the refractive index difference between the ceramic and the solvent ---> penetration depth --> curing thickness
• The bigger the particles, the less the absorbance, the more the curing thickness.
• The bigger the particles, the more the sedimentation and viscosity.
• The more the solid content, the less the curing thickness.
• The more the solid content, the less the sedimentation.
• The lower the viscosity of the resin, the higher the solid content we can add, the higher the curing thickness.
• for curing thickness more than 500 um in ceramics (low absorbance and refractive index): particles size less than 1 um
• SiC curing thickness--> less than SiO2
• polyethylene glycol ratio (7.5%): disperse the Si particles & decrease the viscosity & increase the solid content & increase the density & low the sedimentation
• coarse SiO2: improving the viscosity and the sedimentation performance
• SiO2: interlayer bonding in the deep layer.
• The finer the SiO2, the higher the viscosity, the smaller the curing thickness.
• The finer the SiO2, the less the sedimentation.
• BAPO: high initiating activity and wide absorption wavelength --> diffusing light to the deeper parts to cure the resin
• The ratio of photoinitiator (2%): if low--> high light intensity threshold, if high: curing the resin quickly and preventing the UV to penetrate the layers
• Oxygen: consuming the free radicals (negative effect)
• Exposure energy: Less exposure energy, more printing accuracy, smaller curing thickness.
• More laser power, larger the curing thickness (up to an amount, 147 mW/cm^2).
• The best curing thickness: 120-130 um & the printing accuracy: 70-100 um.
• Too high laser energy : thermal stress--> deformation
• The higher the speed, the less the received energy by the slurry, the smaller the curing thickness.

Stereolithography‐based additive manufacturing of gray‐colored SiC ceramic green body**^[20][edit | edit source]

(Reference 30 for the proper viscosity, spectrometry)

• oxide ceramic colors: white and light
• SiC color: dark and gray --> impact on the light transferring behavior and the ability of curing
• UV light on the ceramic particles (the input light) --> the light energy absorbed by the ceramic particle--> the output light: small
• The absorbance value of the SiC: 0.417
• exposure time: 90 s --> increasing the exposure energy--->increased the curing thickness.
• The smaller the particle size, the worst the curing ability since they absorb more light
• the more the solid content the more the absorbance, the less the curing quality

Stereolithography 3D printing of SiC ceramic with potential for lightweight optical mirror^[21][edit | edit source]

• fabrication of SiC using SLA
• ball milling with zirconia balls for 6 h.
• After printing: polymer burn-out (800), pre-sintering (1800), and precursor infiltration and pyrolysis (PIP)
• the result after PIP: separated silicon, no more layered structure --> making bridges through sintering --> grain boundaries --> denser structure--> still pores due to the burnt out polymer
• PCS--> precursor for PIP --> pore filling
• SiC to resin: 1:1
• total solid loading: 45%
• photoinitiator: 2wt% relative to resin
• dispersant: 5wt% relative to SiC

Materials	Printing setups	Tests
Micron-size SiC (average 15 um)	UV light wavelength: 405 nm light	Archimedes’ method: density
Nano-size SiC (average 40 nm)	thickness: 50 um	three-point bending tests:  flexural strength
Al2O3 (sintering additive)	Exposure energy: 7500 uW/cm2	SEM: microstructure
Y2O3 (sintering additive)	Exposure time: 90 s/first layer	XRD: crystalline phase
HDDA (monomer)	Exposure time: 15 s/other layers
TMPTA (monomer
TPO (photoinitiator)
KOS110 and 17000 (dispersant)
Polycarbosilane (precursor)
DiVinyl-Benzene (solvent)

Dispersion and stability of SiC ceramic slurry for stereolithography^[22][edit | edit source]

• DLP
• the effect of different parameters on the SiC slurry stability: 1) resin, 2) dispersant, 3) particle size, 4) solid loading, and 5) ball milling time
• mixing particles --> ball milling with zirconia (everything together including the dispersant)
• two different monomers (HDDA & TMPTA) with different ratio: effect of resin on the polymerization
• molecular weight of HDDA --> smaller than TMPTA --> the higher the HDDA the lower the viscosity
• viscosity for streolithography: 0-10 Pa.s
• cross-linking degree of HDDA: small --> the higher the HDDA the lower the curing thickness
• curing thickness: 5-10 um higher than the designed sliced thickness
• the higher the HDDA the higher the resin stability
• the effect of the dispersant (4-6%): low concentration--> many particles not modified--> adherence and agglomeration of the particles --> high viscosity
• high concentration: free dispersant molecules in the inter-particle framework --> high viscosity
• best dispersant: 5 % of KOS110 + 17000
• the effect of the particle size: Smaller particles--> high specific surface area & high specific surface energy -->dispersing easier than bigger particles
• small particles: negative effect on the high solid loading --> mix of particles preferable (smaller for dispersion and bigger for solid loading)
• small particles: negative effect on the viscosity --> low curing thickness--> best choice: 0.5 to 1% of nano particle size
• mix of particle size --> no sedimentation
• for particles: 2 forces: gravity & dispersion
• bigger particles: higher gravity
• smaller: almost equal gravity and dispersion force --> good dispersion
• solid loading (40%): the higher the solid loading the better the mechanical properties after sintering
• high solid loading: high viscosity and low curing thickness

Materials	Printing setups	Tests
Micron-size SiC (average 15 um)	UV light wavelength: 405 nm light	Rotational rheometer: rheological performance
Nano-size SiC (average 40 nm)	thickness: 50 um	static sedimentation method: stability of the slurry
HDDA (monomer)	Exposure energy: 7500 uW/cm2	Digital micrometer: curing thickness
TMPTA (monomer)	Exposure time: 30 s	Rotational rheometer: rheological performance
TPO (photoinitiator, 2 wt% relative to the total resin mass)
KOS110, 17000, 20000, 27000, and a KOS110 + 17000 dual (dispersant, )
Polycarbosilane (precursor)
DiVinyl-Benzene (solvent)

Fabrication of SiC ceramic architectures using stereolithography combined with precursor infiltration and pyrolysis^[23][edit | edit source]

• polymer burnt out after printing (800)
• the viscosity for SLA: 5-10 Pa.s
• the higher the solid loading--> the lower the curing thickness
• the higher the solid loading--> the lower the density --> the less the flowability, the more the bubbles along the layer boundaries
• the more the solid load --> the less the amount of resin to connect the particles together--> the more the pores in the structure--> the less the strength
• after the pyrolysis: the higher the solid content the lower the shrinkage

Materials	Printing setups	Tests
SiC (30, 35, 40vol%) (average 1.1 um)	UV light wavelength: 405 nm light	Rotational rheometer: viscosity
HDDA (monomer) and triethyleneglycol divinyl ether (DVE-3) (monomer) (1:1)	Slice layer thickness: 50 um	Archimedes’ method: desnity after polymer burnt out
TPO (free radical photoinitiator, 1wt% based on the slurry weight)	Exposure energy: 7500 uW/cm2	Digital micrometer: curing thickness
(4-Methylphenyl)[4-(2methylpropyl)phenyl] iodonium hexafluorophosphate (cationic photoinitiator, 1wt% based on the slurry weight)	Exposure time: 90 s	TG-DTA: Binder burnout behavior
KOS110 (dispersant, 5wt% based on the slurry weight)		XRD: crystalline phase
		Three-point bending test: strength
		SEM: microstructure

Stereolithography additive manufacturing and sintering approaches of SiC ceramics^[24][edit | edit source]

• temperatures: polymer burnt out: 800, pre-sintering: 1800 in graphite furnace, curing: 60 degrees, pyrolysis 1200
• viscosity: 0.65
• shrinkage after the polymerization: 0.7%

Materials	Printing setups	Tests
Nano- and micron-sized SiC (40vol%)	UV light wavelength: 405 nm light	Archimedes’ method: desnity after polymer burnt out
HDDA (monomer) and TMPTA (monomer)	Slice layer thickness: 25 um	Digital micrometer: linear shrinkage
TPO (free radical photoinitiator, 1wt% based on the slurry weight)	Exposure energy: 7500 uW/cm2	XRD: crystalline phase
KOS110 and 17000 (dispersant, 5wt% based on the slurry weight)	Exposure time: 90 s (first) & 15 s (others)	Three-point bending test: strength
		SEM: microstructure

Mechanochemical Synthesis of Fe−Si-Based Anode Materials for High-Energy Lithium Ion Full-Cells^[25][edit | edit source]

• ball milling the Si powder with Fe powder
• WC balls
• drum volume: 80 mL & powder mass: 2.5 gr & rotational speed: 350 rpm
• Fe to Si ratio: 14:86 (here the weight ratio is 1:3), 20:80, 25:75, 33:67 atom %.
• heat treatment: 750 or 100 degrees for 10 h
• adding graphite (15%) & milling
• final mass ratio of active material, PAA binder and conductive agent: 85:10:5
• After milling more than 120 min: Fe to inactive Fe Si2
• more FeSi2 more stable cycling performance less reversible specific capacity, capacity retention, average lithiation and delithiation potential, or initial CE
• the smallest crystallite size while increasing the crystallite size --> the longest cycle life & reducing the cycle life

Tests
XRD: investigation the bulk structure. Micrometrics by physisorption surface analyzer: to measure the specific surface area. BET Raman SEM EDX Tapped density analyzer Particle size analyzer: for particle size distribution TGA

Properties of Fe–Si Alloy Anode for Lithium-Ion Battery Synthesized Using Mechanical Milling^[26][edit | edit source]

• Si: Fe -->85:15
• ball to powder ratio--> 15:1
• speed: 650 rpm
• binder: PAA
• alpha FeSi2: metallic high temperature & beta FeSi2: semiconducting low-temperature
• after milling: Si surrounded by FeSi2
• when alpha FeSi2: high conductivity
• more ball milling --> beta FeSi2 --> less conductivity
• more milling time: SEI inside the particles

Silicon-Based Lithium-Ion Battery Systems: State-of-the-Art from Half and Full Cell Viewpoint[edit | edit source]

• SiOx --> less volume change but the side reactions --> formation of by-products & poor CE--> compensate by modifications.
• Electrolyte decomposition & SEI formation <-- plateau from 0.8 to 1.2 v
• reacting Si and Li+ --> 0.1-0.2 v
• Fracture of Si--> SEI breakdown --> consuming more Li+
• Solution1: Using polymer binder ---> but strong adhesion in polymer --> mechanical fatigue
• Solution 2: increasing the content of hydrogen bonds
• Solution 3: developing highly elastic polymer binders
• Solution 4: Prelithiation
• bulk silicon:
  • higher ICE in micro size silicone but particle fracture and electrochemical polarization
  • ball milling Si waste with SiC and Ni --> composite containing Si-SiC-Ni
  • treating Si with ether and nitric acid and then co-sintering with graphite and sucrose --> SiC
• core-shell structure:
  • solving silicon powders to the polymer (PVB) and then pyrolysis
• -------------

Research progress on silicon/carbon composite anode materials for lithium-ion battery[edit | edit source]

• SiC composite:
  • core-shell
  • yolk-shell
  • porous structure
  • embedding structure
• Core shell:
  • carbon sources: sucrose, resin, acrylonitrile, polyvinyl alcohol (PVA), polyoxyethylene (PEO), polyvinyl chloride (PVC), polyethylene (PE), chlorinated polyethylene (CPE), pitch and polyvinylidene fluoride (PVDF) (the most optimum one)
  • In SiO: li in the structure--> forming Li4SiO4 ---> mechanical support
• Yolk-shell:
  • coating silicon wit SiO2 --> coat with another layer mesoporous (for resin diffusion) ---> converting the resin to C by heating
  • acid washing --> solving O---> Si/void/ carbon
  • more voids --> less structure degradation
• porous structure: providing path for the li ion penetration and volume change alleviation--> 3D printing
• getting p-Si/C or Si/p-C
• p-Si: magneseiothermic --> expensive
• SiOx /C:
• better cycling performance of SiO2 --> Si-O--> stronger bonds than Si-Si & producing lithium silicate and Li2O --> volume change alleviation --> carbon coating--> higher efficiency
• SiOx--> commercially used--> low ICE <-- irreversible electrochemical reaction between lithium ion and SiO2
• embedding type:

The synergistic effects of combining the high energy mechanical milling and wet milling on Si negative electrode materials for lithium ion battery^[27][edit | edit source]

• combination of ball milling and wet milling.
• The silicon powder --> submicron and nano size.
• The process fractured the silicon particles
• The powders --> in amorphous and nanocrysralline phases.
• The wet milling --> enhance the SEI formation --> trigger the Si-O-CH2CH3 bonding on Si surface.
• The powder --> suppress the formation of the Li15Si14 during lithiation and delithiation <--- crystallin structure.

Si:C:Binder	65:20:15
Si active material loading	0.9 mg /cm2
coin-type	2032 coin-type cells
counter electrode	lithium foil
Separator	Celgard 2300
Electrolyte	1 M LiPF6 in a mixture of ethylene carbonate (EC, Ferro Co.), dimethyl carbonate (DMC, Ferro Co.) (1:1 by weight) and additive of 10 wt% fluorinated ethylene carbonate (FEC, Sigma-Aldrich Co.)
discharge (lithiation)/charge (delithiation)	0.02 and 1.5 V versus Liþ/Li
Cyclic voltammetry (CV)	potential range of 0.005e2 V (vs. Liþ/Li)
Cyclic voltammetry (CV) scan rate	scan rate of 0.1 mV /s[edit | edit source]

A novel approach to synthesize micrometer-sized porous silicon as a high performance anode for lithium-ion batteries^[28][edit | edit source]

• microemulsion of cost-effective silica nanoparticles and magnesiothermic reduction
• Spherical micron-sized p-Si particles from this approach:
• Consist of highly aligned nano-sized silicon
• Exhibit tap density similar to bulk Si particles
• Improved electrochemical stability compared to nano-Si
• Features well-controlled void space and highly graphitic carbon coating on p-Si particles
• High tap density due to close packing structure (micrometer size silicon)
• High volumetric capacity of electrode (high tap density)
• Particle size range: 500 nm to 10 um, average: 5.28 um
• Wider particle size range results in higher tap density
• Nanometer pores inside structure (ability to buffer volume change)
• Silicon surface modified with carbon coating
• Carbon coating thickness: 5nm
• TGA: Determines carbon amount on silicon parts (17.3 wt%)
• Carbon coating is graphitic in nature
• Homogeneous distribution of carbon particles in silicon (improves electrochemical performance)

Benchmarking the Effect of Particle Size on Silicon Anode Materials for Lithium-Ion Batteries^[29][edit | edit source]

• Crystal-to-amorphous phase transition during cycling (nano and micro size silicon)
• Different composition transition during de/lithiation (nano and micro size silicon)
• Thinner SEI in micro size
• Different composition of SEI (micro and nano size)
• Micro-size silicon powders prepared by ball milling

Effect of Size and Shape on Electrochemical Performance of Nano-Silicon-Based Lithium Battery^[30][edit | edit source]

• Silicon nanoparticles vs. silicon nanowires comparison:
• Nanoparticles have higher initial specific capacity (3000-3500 mAh/g vs. 2500-300 for nanowires).
• Coulombic efficiency correlates linearly with silicon's specific area.
• Long-term cycling:
• Nanoparticles exhibit faster fade due to internal resistance.
• Nanowires show cycle stability.
• Critical diameter ranges:
• Nanoparticles and nanowires both in the range of 70-150 nm (not reliable due to different silicon sources, high size distribution, narrow average size range).
• Nanoparticles also in the range of 20-50 nm.
• Nanowires around 30 nm.
• Active material, conductive material, binder percentage: 50:25:25 (%).
• Carbon black contributes 100 Ah/g in specific capacity when measured independently.

Preparation of high solid loading and low viscosity ceramic slurries for photopolymerization-based 3D printing^[31][edit | edit source]

• Smaller particle size → higher viscosity
• Higher solid volume fraction → higher viscosity
• 5% dispersant → lowest viscosity
• 2% photoinitiator → optimal curing process
• 40% solid loading → thickest curing depth
• Proper solid load particle size after ball milling: 0.35 um
• Ball milling done with zirconia balls
• Ball mill used as the mixing device
• Ball milling can trap air in the solvent, requiring consideration of defoamer agent or vacuum defoaming
• Lower viscosity is desirable, achieved with larger particles and lower solid content, but sedimentation increases
• Sedimentation is more important for print resolution
• Trade-off between sedimentation and viscosity
• Particle size most important factor in sedimentation; smaller size leads to less sedimentation
• Larger particles allow for higher solid load in the resin
• Longer exposure time results in thicker curing
• More photoinitiator (up to 2wt%) leads to thicker curing
• Excess photoinitiator can cause light absorption or scattering
• Increasing solid content reduces penetration depth and critical exposure
• Sliced layer thickness of printed sample should be smaller than penetration depth
• For 100 um sliced layer, maximum solid content is 40%, and particle size should be less than 3 um.

Materials	Cordierite powder (solid content)
	TMPTA: monomer
	HDDA: monomer
	propyl trimethoxysilane: surfactant
	Disperbyk-111: dispersant
	TPO: photoinitiator
Printing setups	critical exposure density: 0.73 and 2.73 mJ/cm2
Tests	DLS: particle size
	Rheometer: viscosity as a function of shear rate
	Still settling tests: the stability of the slurries after preparation

Controlling Surface Oxides in Si/C Nanocomposite Anodes for High-Performance Li-Ion Batteries^[32][edit | edit source]

• Si oxide obtained by heating Si particles in the oven
• Time and temperature varied to control oxide layer thickness
• DMF and PAN used as carbon sources
• Core Si: crystalline structure, amorphous Si oxide surroundings
• FTIR results: Si-O-Si bonds, SiO4 bonds, O-Si-O bonds
• Carbon structure: floc-like, prevents Si agglomeration, forms conductive porous network
• Increasing oxide layer: SiOx to SiO2 transformation (negatively affects electrochemical, positively affects mechanical)
• Adjust oxide layer for different properties (e.g., 5 nm for high capacity, 8 nm for better cycling)
• 5 nm thickness: high capacity and cycle stability
• Thicker surface (>5 nm): better cycle stability, lower capacity due to limited lithiation

Silicon-Based Lithium-Ion Battery Systems: State-of-the-Art from Half and Full Cell Viewpoint^[33][edit | edit source]

• SiOx:
  • less volume change, side reactions, by-products, poor CE
  • Electrolyte decomposition, SEI formation related to 0.8-1.2 V plateau
  • Si and Li+ react at 0.1-0.2 V
  • Fracture of Si results in SEI breakdown, consumes more Li+
  • Polymer binder solution, but strong adhesion can lead to mechanical fatigue
  • Increasing hydrogen bonds content as a solution
  • Developing highly elastic polymer binders
  • Crosslinking of Si/CNT
  • Prelithiation for increased efficiency
• Bulk Si:
  • Microsize Si higher ICE than nano-sized Si, but particle fracture and electrochemical polarization
  • Reference 96: ball milling Si waste with SiC and Ni to create Si-SiC-Ni composite
  • References 202, 203, 204: treating Si waste with ether and nitric acid, co-sintering with graphite and sucrose to obtain Si/C
• Core-Shell Structured Si Materials:
  • Reference 205: core-shell Si/C created by dissolving Si powders into PVB polymer, then pyrolysis
  • Reference 102: Si @ void @ C
  • Reference 206: SiO2 covered by C, then Magnesiothermic treatment, possibly resulting in Si particles with double carbon coatings.

Research progress on silicon/carbon composite anode materials for lithium-ion battery^[34][edit | edit source]

• Si-C Composite Categories:
  1. Core-shell:
     • Carbon sources: sucrose, resin, acrylonitrile, PVA, PEO, PVC, PE, CPE, pitch, PVDF (optimal morphological performance).
     • Doping Si with an element and then C improves results.
     • Li+ penetration into SiO2 structure forms Li4SiO4 for mechanical support.
  2. Yolk-shell:
     • Si coated with SiO2, then mesoporous layer for resin infiltration.
     • Heating converts resin to C, acid washing removes SiO2, yielding Si/void/C.
     • More void results in less structural degradation.
  3. Porous structure (for Li intercalation and volume alleviation):
     • p-Si/C or Si/p-C structures.
     • Making p-Si and p-C is complex; research ongoing.
     • Larger porous particles needed for increased tap/packing density.
  4. SiOx/C type:
     • SiOx structure has Si particles homogeneously distributed in SiO2 matrix.
     • Si-O bonds are twice as strong as Si-Si bonds, leading to excellent cycle performance.
     • Carbon coating improves efficiency.
     • Low initial coulombic efficiency due to irreversible electrochemical reaction with SiO2; prelithiation helps.
  5. Embedding type:
     • Silicone embedded in continuous carbon matrix as buffer.
     • Graphite:
       • Si particles intercalated between graphite flakes.
       • Graphite stabilizes SEI layer, prevents Si particle agglomeration, and enhances electrical conductivity.
       • Milling or CVD used to achieve structure.
       • Poor adhesion requires polymer binder for interface bonding (e.g., Si/graphite/PAN, pelletizing, or ball milling with glucose and PVP).
     • CNT/CNF:
       • Si nanowires or nanotubes improve Li and electron transport but challenging electrode fabrication.
     • Binders for Si:
       • Traditional PVDF not suitable due to weak van der Waals interactions.
       • New binders: carboxymethyl cellulose, polylactic acid-based, and alginate-based polymers form hydrogen bonds and/or covalent chemical bonds.
       • More adhesion leads to greater Si involvement in reactions.
       • 3D polymer chains (crosslinking) desired for stability.
       • Abundant hydrogen bonds create self-healing properties for Si anode stabilization.

Si anode for next-generation lithium-ion battery^[35][edit | edit source]

• Problems with Li-Si alloying and dealloying:
  • Loss of electric contact with current collector and conductive materials.
  • SEI formation causing irreversible capacity and poor cycling performance.
  • Cracking and pulverization of Si.
• Particle size effect:
  • Particles below 150 nm are desirable.
• Compositing effect:
  • Provides mechanical strength.
  • Enhances conductivity.
  • Reduces contact area between electrolyte and active material.
  • Composite matrixes include graphitic and amorphous carbon, metals, and oxides like MXene.
  • Surface modification with organic functional groups helps form stable interfaces and maintain structural integrity.
• SiOx:
  • Low volume change but large initial irreversible capacity in the first cycle due to Li2O and lithium silicate formation.
• Effective parameters on composite performance:
  • Si and graphite size.
  • Mass ratio of Si and graphite.
  • Si distribution.
  • Voids between electrodes.
  • Preparation method.
• Structure design effect:
  • Voids important for relieving deformable stress.
  • Prevent electrical isolation formation, maintaining integrity.
  • Different designs include solid Si core and hollow shell, porous shell, solid shell, porous Si core with solid shell, nanostructured Si embedded in porous and flaky matrix.
• Binder effect:
  • Binders responsible for cohesion, should have stability, conductivity, self-healing, low cost, and eco-friendliness.
  • Common binder, PVDF, lacks adequate integrity due to weak van der Waals forces.
  • Alternatives: water-soluble binders, natural gum, hydrogel alginate, ion- and electron-conducting polymers, 3D network.
• Electrolyte additives:
  • Characteristics include higher reductive potential, chemical compatibility, and film-forming properties.
  • Impact morphology and composition of SEI.
  • Examples: vinylene carbonate, fluoroethylene carbonate (for cycling stability and CE).
  • Carbonate additives lead to crosslinked PEO and organic SEI components bonding to Si covalently.
• Conductive additives:
  • Can be carbon black, CNT, CNW, Gr.
  • Require excellent electrical conductivity, stability, strength, flexibility, and low cost.
• Structure considerations:
  • 3D design of binder-free anode on current collector: promotes ion and electron transportation, strengthens Si-current collector contact, avoids detachment.
  • Thin carbon layer: continuous electron path.
  • Interconnection: fast ion/electron diffusion and increased electrode density.
  • Porous SiNW: stress release and short ion diffusion path.
  • 3D conductive framework within Si-based electrode: increases mass loading density, enhances mechanical property and electron migration, retards structural degradation.
• 3D current collector.
  • Proper positive electrode choice to stabilize Si alloy in the negative electrode, e.g., LNMCO releases CO2.
• Advanced characterization techniques
  • in-situ TEM to observe morphological changes (volume expansion) during lithiation and delithiation.
  • Macropores in structure for stress reduction, thinner SEI layer, and better electrical contact.
• SEI layer:
  • a passivation layer forming naturally on the electrode surface to avoid further reactions between electrode and electrolyte.

Using carbon black to facilitate fast charging in lithium-ion batteries^[36][edit | edit source]

• Carbon black lattice space larger than graphite, enables fast charging.
• Work focuses on modifying CB content of graphite --> enhances energy density, and fast charging in Li-ion batteries.

Areal capacity of the anode	3 mAh/cm^2
Anode Porosity	33%
Coin cell	coin cells (CR-2032)
CD	voltage window of 0.01-2.0 V
CD rate	under a 0.1C
Anode loading	9.8, 8.57, 8.92, 9.21, 9.81 mg/cm^2

Effect of Particle Size and Surface Treatment on Si/Graphene Nanocomposite Lithium-Ion Battery Anodes^[37][edit | edit source]

• Four particle size ranges: 20-30 nm, 30-50 nm, 100 nm, 1-5 um.
• Silicon particles between graphene sheets.
• Bigger particles for more tap density.
• Higher tap density means higher loading weight.
• 20-30 nm highest specific surface area: higher surface area, less ion transportation path. More electrolyte consumption for SEI formation.
• Nanometer-sized silicon: round; micrometer-sized: flakes.
• Graphene: wrinkle flake.
• Composites show uniform distribution of Si, C, O.
• Micrometer size: highest crystallinity.

Si:C:binder	70:15:15
coin cell	half- CR2032 coin cells
counter electrode	Lithium foil
electrolyte	1 M LiPF6 dissolved in a mixed solution of diethyl carbonate (DEC) and ethyl carbonate (EC) at 1:1 vol ratio with 2 wt% fluoroethylene carbonate (FEC, 99%, Sigma-Aldrich) as additive
CD voltage	between 0.001 and 1.5 V
CD current rates	different current rates calculated based on the theoretical capacity of lithiated Li15Si4 at 3,579 mAh/g

Si/SiC/C in-situ composite microspindles as anode materials for lithium-ion batteries[edit | edit source]

• Si/SiC/C in-situ composite microspindle fabrication process
• Utilization of Zn2SiO4/C nanowire bundles from hydrothermal synthesis
• In-situ generation and uniform distribution of SiC and C components
• Strengthening effect of SiC on microspindle structure
• High conductivity and buffering function of amorphous carbon
• Application as anode materials in lithium-ion batteries
• Reversible charge capacity of 1510 mAh g-1
• Initial coulombic efficiency of 78.7%
• Capacity retention of 89.9% after 200 cycles at 100 mA g-1
• Superior rate capability
• Enhanced electrochemical performance compared to pure Si microspindles
• Efficiency of composition and structural design of Si/SiC/C composite microspindles