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Lithium-ion batteries have revolutionized modern energy storage systems, powering everything from portable electronic devices to electric vehicles (EVs). As the demand for higher energy density, enhanced safety, and faster charging grows, researchers continue to look for innovative materials and processes to overcome the limitations of conventional graphite-based anodes.
Silicon as an anode active material, with exceptionally high theoretical capacity, has emerged as a promising candidate for advancing cost effective, fast-charging, safe, Li-ion batteries. However, its reactivity demands careful handling in a non-oxidizing environment during production.
To address this challenge, researchers are - amongst other solutions - exploring various methods of passivation as a critical strategy.
StoreDot’s patented innovation describes methods of preparing anode material particles, mixtures, and electrodes for fast charging lithium-ion batteries. These methods incorporate passivated silicon-based particles, allowing for efficient processing of the anode in oxidizing environments, including water-based slurries.
StoreDot’s invention describes a method of creating an anode-material from silicon (Si) particles coated with passivation layers. The particles’ passivated layers inhibit reactions of the Si when exposed to oxidizing environments such as when consolidated with binder and conductive materials in a water-based slurry.
The patent lays out a process for creating a mixture of silicon particles with nanoparticles (NPs) and a carbon-based binder and/or surfactant. The NPs provide nucleation sites for the passivation layer on the surface of the silicon particles – allowing for significant simplification of the anode-formation process by enabling processes that rely on water-based slurries.
The NPs can include metalloid oxide NPs, metalloid salt NPs, Sb and/or Cu salt NPs, Sn, Sb, Cu, SnSb alloy and/or SnCu alloy NPs, metallic Ag, Au, Pb and/or Ge NPs, and carbon NPs.
Once reduced, the mixture containing the passivated silicon particles can be consolidated to form an anode.
By employing passivated silicon particles, StoreDots invention not only simplifies the manufacturing procedure by enabling the processing of Si anode materials in oxidizing environments such as encountered when using water-based slurries, but ultimately boosts the cost-effective, sustainable production of high performance anodes for fast charging EV batteries.
