Shanghai Semitech New Material Co., Ltd.
1628 Lijing Road, Lingang New Area, 200000, Shanghai, China.
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+8615639100440
Email:
info@semitechnm.com
Lithium Battery Materials
Application Hub Lithium Battery Cell-to-Pack
Lithium Battery Materials
Specialty additives across separator, cathode, electrolyte, TIM and pack
SEMITECH supplies fumed metal oxides and silicone-based additives for lithium-ion and semi-solid battery manufacturers — engineered for high-Ni cathode stability, separator thermal integrity, electrolyte gelation, and pack thermal management.
Contents
SEMITECH at a glance
Material families5
Battery solutions5
Custom gradesYes
Sample availableYes
Why specialty additives matter for Li-ion
As cell energy density climbs and pack architectures move toward cell-to-pack and cell-to-chassis designs, specialty inorganic and silicone additives have moved from formulation tweaks to structural enablers.
Three pressures converge on every modern lithium battery. Thermal runaway prevention demands ceramic-coated separators and flame-retardant pack materials. Energy density pushes the industry toward high-nickel cathodes, which bring surface instability and gas evolution challenges. Cycle life hinges on SEI integrity and electrode-electrolyte interfaces. SEMITECH’s portfolio of fumed metal oxides and silicone chemistry addresses each of these pressures with field-proven materials.
Battery anatomy and material map
SEMITECH materials sit at five critical insertion points across the cell-to-pack architecture:
Cell-level — separator coating (fumed alumina, fumed silica), cathode surface coating (fumed alumina), electrolyte gelation (fumed silica).
Pack-level — thermal interface materials (vinyl + hydrogen silicone fluid), encapsulation and ESS anti-corrosion (MESIL OH polymer, anti-corrosive pigment).
Pack-level — thermal interface materials (vinyl + hydrogen silicone fluid), encapsulation and ESS anti-corrosion (MESIL OH polymer, anti-corrosive pigment).
Five solution areas
1 · Separator Ceramic Coating
Fumed alumina and fumed silica raise separator thermal stability above 180 °C, suppress shrinkage, and improve electrolyte wettability for high-energy NMC and NCA cells.
2 · High-Ni Cathode Surface Engineering
Nano-grade fumed alumina coating suppresses cation mixing on Ni-rich cathodes, reduces gas evolution during cycling, and extends calendar life under elevated temperatures.
3 · Electrolyte Gelation & Semi-Solid
Hydrophilic and hydrophobic fumed silica grades enable gel polymer electrolytes (GPE), reduce free liquid leakage, and serve as inorganic fillers for semi-solid formulations.
4 · Pack Thermal Interface Materials
Vinyl-terminated and hydrogen-functional silicone fluids form the base chemistry for two-component addition-cure TIMs, gap fillers, and thermal pads bridging cells to cooling plates.
5 · Pack Encapsulation & ESS Anti-Corrosion
MESIL OH polymer is the silanol-terminated PDMS base for one-component RTV potting compounds and module sealants. Anti-corrosive pigment supports outdoor energy storage container coatings.
Battery manufacturing process flow
Where SEMITECH materials enter the cell-to-pack workflow:
STEP 1
Slurry Prep
Fumed Silica
Cathode and coating slurry rheology and anti-settling.
STEP 2
Coating
Fumed Alumina
Separator ceramic layer; high-Ni cathode surface coat.
STEP 3
Cell Assembly
Fumed Silica (GPE)
Electrolyte gelation in semi-solid formats.
STEP 4
Module / Pack
Silicone TIM + RTV
Thermal interface, gap-fill, potting and module sealing.
Selection guide
| Battery Layer | Function | SEMITECH Product | Reference Grade |
|---|---|---|---|
| Separator | Ceramic coating | Fumed Alumina | SEMIAL series |
| Separator | Coating slurry rheology | Fumed Silica | SEMISIL 200 |
| Cathode (high-Ni) | Surface coating | Fumed Alumina (nano) | SEMIAL nano |
| Electrolyte | GPE / semi-solid filler | Fumed Silica | SEMISIL 200 |
| Module TIM | Addition-cure base | Vinyl Silicone Fluid | MESIL VTM |
| Module TIM | Crosslinker | Hydrogen Silicone Fluid | MESIL HSF |
| Pack | RTV potting / sealing | MESIL OH Polymer | MESIL-OH |
| ESS Container | Outdoor anti-corrosion | Anti-Corrosive Pigment | SEMICOR series |
FAQ
Why use fumed alumina rather than boehmite for separator coating?
Both work. Fumed alumina (γ-Al₂O₃) offers higher surface area and stronger ion adsorption sites; boehmite (γ-AlOOH) is denser and lower cost. For high-end NMC811 and beyond, fumed alumina’s higher purity and finer particle size improve dimensional stability above 180 °C.
Can fumed silica replace PVDF in electrolyte gelation?
Not directly. PVDF acts as the polymer matrix while fumed silica acts as the inorganic gelling agent — they are complementary. Typical GPE formulations combine 1–3 wt % fumed silica with 5–10 wt % PVDF-HFP for synergistic gelation.
How is TIM viscosity selected for battery modules?
Gap-fillers between cells and cooling plates typically target 50,000–500,000 cP for dispense-grade TIMs. Lower viscosity enables fine dispense for narrow gaps; higher viscosity improves hold on vertical surfaces. SEMITECH offers vinyl and hydrogen silicone bases at multiple viscosity grades for formulators to dial in.
Are SEMITECH silicones compatible with EC/DEC/EMC electrolytes?
Cured silicone elastomers are chemically inert toward standard carbonate electrolytes and lithium hexafluorophosphate (LiPF₆) at typical operating temperatures (< 60 °C). For prolonged contact above 80 °C, our team recommends platinum-cured systems with low-extractable formulations — request the compatibility datasheet.
What loading of fumed silica is typical in gel polymer electrolyte?
Most published GPE formulations use 1–5 wt % fumed silica relative to electrolyte, with 2–3 wt % being a common starting point. Hydrophobic-treated grades (HMDS or PDMS surface modification) improve compatibility with carbonate solvents.
Does SEMITECH support semi-solid battery R&D?
Yes. We provide hydrophilic and surface-modified hydrophobic fumed silica grades, plus fumed alumina nano-grades, for solid-state and semi-solid pilot lines. Our technical team assists with surface chemistry selection, compatibility testing, and small-batch custom modification.
What grades of fumed alumina suit high-Ni cathodes?
For NMC811 and NCA surface coating, target nano-grade fumed alumina with primary particle size 13–20 nm and BET surface area > 100 m²/g. Coating thickness in the 2–5 nm range typically suppresses cation mixing without sacrificing rate capability.
Do you offer custom samples for new formulations?
Yes. Standard grades ship in 100 g, 1 kg, and 25 kg trial sizes. Surface-modified or particle-size-targeted custom grades require an NDA and 4–8 week pilot lead time. Contact our applications team to scope a sample protocol.
Detailed datasheets, chemical compatibility data, and certificate of analysis available upon request. Last updated April 2026.