Anode material for aqueous lithium secondary batteries and manufacturing method thereof

LiV3O8 Anode for Aqueous Lithium Batteries with Suppressed Vanadium Dissolution via AlF3 Coating

This technology is an anode material for aqueous electrolyte lithium secondary batteries, featuring an aluminum fluoride (AlF3) coating layer on the surface of LiV3O8 particles, and a method for its production. The coating layer is created by mixing LiV3O8 with a metal fluoride precursor solution, drying the mixture, and calcining it in an argon atmosphere.

While aqueous lithium secondary batteries avoid the flammability and toxicity issues of non-aqueous electrolytes, the narrow electrochemical stability window of water has limited the available anode materials. LiV3O8, a promising anode candidate, has suffered from poor cycle performance due to low electronic conductivity, vanadium ion dissolution, and the formation of unwanted side-reaction products.

In this technology, the AlF3 coating layer reduces direct contact between the aqueous electrolyte and the active material, thereby decreasing vanadium ion dissolution and surface defects while preventing the formation of side-reaction components and promoting lithium-ion diffusion. The coating amount is controlled between 0.1 and 3 wt% to enhance surface stability without compromising conductivity. It can be applied to anodes for large-capacity energy storage aqueous lithium secondary batteries, contributing to extended battery life with reduced fire risks.

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Key Features:

• A step of obtaining a mixed solution by mixing LiV3O8 particles, which are the anode active material, with a metal fluoride MeFx precursor solution
• A step of obtaining a dried product by drying the mixed solution at 130 to 140°C for 30 minutes to 2 hours
• A step of calcining the dried product in an argon atmosphere at 300 to 500°C for 1 to 3 hours
• An anode material for aqueous electrolyte lithium secondary batteries using AlF3 as the MeFx, where the AlF3 coating amount is 0.1 to 3 wt% relative to the LiV3O8 particles

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This invention was developed with support from the Ministry of Science and ICT for the development of egg-shell structured cathode materials through spontaneous ion exchange to overcome the capacity limitations of secondary batteries.

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