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.
FAMILIES 5 SOLUTIONS 5 UPDATED Apr 2026
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 designs, specialty inorganic and silicone additives have moved from formulation tweaks to structural enablers — addressing thermal runaway prevention, high-nickel cathode surface instability, and SEI integrity.
Battery anatomy and material map
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).
Five solution areas
Fumed alumina and fumed silica raise separator thermal stability above 180 °C, suppress shrinkage, and improve electrolyte wettability.
Nano-grade fumed alumina suppresses cation mixing on Ni-rich cathodes, reduces gas evolution, and extends calendar life.
Hydrophilic and hydrophobic fumed silica grades enable gel polymer electrolytes and reduce free liquid leakage.
Vinyl-terminated and hydrogen-functional silicone fluids form the base chemistry for two-component addition-cure TIMs and gap fillers.
MESIL OH polymer is the silanol-terminated PDMS base for RTV potting compounds and module sealants.
Battery manufacturing process flow
- STEP 1Slurry PrepFumed Silica
Cathode and coating slurry rheology and anti-settling.
- STEP 2CoatingFumed Alumina
Separator ceramic layer; high-Ni cathode surface coat.
- STEP 3Cell AssemblyFumed Silica (GPE)
Electrolyte gelation in semi-solid formats.
- STEP 4Module / PackSilicone 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?
Fumed alumina (γ-Al₂O₃) offers higher surface area and stronger ion adsorption. For NMC811 and beyond, its higher purity and finer particle size improve dimensional stability above 180 °C.
+Can fumed silica replace PVDF in electrolyte gelation?
Not directly — 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 target 50,000–500,000 cP. Lower viscosity enables fine dispense for narrow gaps; higher viscosity improves hold on vertical surfaces.
+What loading of fumed silica is typical in gel polymer electrolyte?
Most formulations use 1–5 wt%, with 2–3 wt% as a common starting point. Hydrophobic-treated grades improve compatibility with carbonate solvents.
+What grades of fumed alumina suit high-Ni cathodes?
Target nano-grade with primary particle size 13–20 nm and BET > 100 m²/g. Coating thickness of 2–5 nm 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. Custom grades require an NDA and 4–8 week pilot lead time.