Applications of green silicon carbide micropowder in lithium batteries & new energy storage materials
Green silicon carbide’s core characteristics: high purity insulation, high temperature resistance, resistance to electrolyte corrosion, high thermal conductivity, and low heavy metal impurities, strictly distinguishing it from conductive black silicon carbide. Black silicon carbide is conductive and prone to causing micro-short circuits in the battery cell; therefore, only green silicon carbide can be used in core lithium battery safety scenarios. It covers six major sectors: separators, cell materials, PACK packaging, equipment protection, solid-state batteries, and energy storage auxiliary materials.
I. Ceramic coating for lithium battery separators
High-end power lithium batteries and long-cycle energy storage batteries utilize a composite ceramic slurry of alumina and green silicon carbide.
High Temperature Resistance
Instantaneously withstands temperatures up to 1500℃. During battery puncture and thermal runaway, the ceramic layer skeleton does not melt, locking the separator size and preventing large-area contact between positive and negative electrodes, significantly reducing the risk of thermal runaway.
Insulation Guarantee
Green silicon carbide provides high insulation, preventing particle conductivity from causing micro-short circuits in the cell; black silicon carbide is conductive, making its use strictly prohibited in lithium battery separators.
Electrolyte Resistance
Extremely chemically inert, it does not dissolve or corrode even after long-term immersion in carbonate electrolytes, preventing electrolyte contamination and cycle degradation.
Abrasion and Puncture Resistance
High hardness prevents coating powder from easily falling off during rolling, slitting, and winding processes, avoiding powder blockage of electrode pores; inhibits lithium dendrite punctures into the separator.
II. Composite Modification Materials for Battery Cell Electrodes and Anodes
1. Graphite Anode Coating Modification
Nano-green silicon carbide micropowder is used to coat the surface of natural and artificial graphite as a composite filler for the anode:
Rigid particles buffer the expansion of graphite after lithium intercalation, alleviating electrode pulverization and increasing cycle life by over 30%;
A stable SEI passivation film is formed on the surface, reducing continuous side reactions in the electrolyte and lowering electrolyte consumption;
Improved anode thermal conductivity allows for rapid heat dissipation during fast charging, reducing the risk of localized overheating of the electrode.
2. Silicon-Carbon Anode Reinforcement
Silicon-carbon anodes have a high expansion rate. Incorporating ultrafine green silicon carbide provides high hardness for rigid support, improving electrode toughness; simultaneously, it ensures uniform thermal conductivity, resolving the issue of localized hot spots in silicon-based anodes.
III. PACK Energy Storage Modules: Insulating and Thermally Conductive Potting Compounds, Structural Adhesives and Fillers
Epoxy/silicone potting compounds are widely used in energy storage battery packs, BMS motherboards, high-voltage copper busbars, and terminal blocks. Green silicon carbide is the preferred filler for thermal conductivity and insulation, perfectly solving industry pain points:
Dual Achievement of Thermal Conductivity and Insulation
Thermal conductivity 120~150W/m・K, far higher than alumina; when filled with silicone or epoxy, the module’s charging and discharging heat is quickly dissipated; simultaneously, its extremely high volume resistivity ensures insulation and prevents creepage under high voltage, making it suitable for high-voltage energy storage PACKs (800V platform).
Graphite and black silicon carbide are thermally conductive but electrically conductive, and high-voltage potting can lead to leakage and short circuits; alumina has relatively low thermal conductivity.
Resistant to Electrolyte and Humid Heat
Energy storage environments experience large temperature differences and are prone to condensation.
Green silicon carbide is resistant to acids and alkalis and hydrolysis, ensuring that the potting compound does not crack or fail to provide insulation over long-term outdoor use.
IV. Special Insulating, Wear-Resistant, and Corrosion-Resistant Coatings for Lithium Battery Production Line Equipment
The topcoat and roller surface protective coatings for coating machines, roller presses, slitting machines, formation equipment, and energy storage testing fixtures must all use green silicon carbide; black silicon carbide cannot be used.
Insulation Requirements
For equipment with weak current or high-voltage control, the coating must be insulating to prevent leakage and battery cell breakdown.
Wear and Corrosion Resistance
To prevent electrode dust and electrolyte splashes from corroding the equipment, green silicon carbide increases the hardness of the coating film, providing resistance to electrolyte erosion and friction.
High Temperature Resistance
The coating will not chalk or crack even after prolonged exposure to high temperatures (120~180℃) in the coating oven.
V. Key Fillers for Solid-State Lithium Batteries
1. Oxide-based Solid-State Electrolyte Composite with Green Silicon Carbide Micropowder
Improves the mechanical strength of the solid-state electrolyte and inhibits lithium dendrite penetration; simultaneously optimizes thermal conductivity, solving the problem of concentrated heat generation due to internal resistance in solid-state batteries; chemically stable and does not undergo side reactions with the solid-state electrolyte.
2. Solid-State Cell Encapsulation Ceramic Composite Resin
Green silicon carbide-filled resin, high-temperature resistant, insulating, and deformation-resistant, suitable for the high-temperature sintering process of solid-state batteries.
VI. Energy Storage Supporting Materials and Ceramic Structural Components
1. Lithium-ion Battery Ceramic Functional Components (Sintering Main Material)
Silicon carbide ceramics sintered from green silicon carbide micropowder are used to manufacture components for the energy storage industry:
Electrode cutting ceramic blades and ceramic rollers; wear-resistant and insulating, they will not scratch the electrodes and will not contaminate the battery cells with metal debris;
Battery sintering kilns and firing plates; resistant to high temperatures and lithium-ion battery sintering atmosphere corrosion, suitable for sintering battery cell materials.
2. Electrolyte Filtration and Corrosion-resistant Piping Fittings
Green silicon carbide ceramic filter elements and pipes, resistant to electrolyte corrosion, are used for electrolyte circulation filtration and transportation pipelines in energy storage.
VII. Insulating and Heat-Dissipating Plastics for Energy Storage BMS and High-Voltage Components
Energy storage junction boxes, high-voltage connectors, and IGBT heat dissipation and insulation brackets mostly use modified engineering plastics such as PPS, PEEK, and PA66, with green silicon carbide as a modified filler:
1. High thermal conductivity for heat dissipation, solving the problem of heat generation in energy storage power devices;
2. Full insulation, preventing high-voltage conduction and leakage;
3. Resistant to electrolytes and high/low temperature aging, suitable for long-term outdoor energy storage use.