Lithium metal battery comprising electrodes with solid additives

Long-Life Lithium Metal Batteries Using Bipyridine/Bipyridinium COF as Cathode Additives and Anode Coatings

This technology prevents performance degradation in lithium metal batteries by incorporating 2,2'-bipyridine-based covalent organic frameworks (COFs) into the cathode active material layer and 2,2'-bipyridinium-based COFs into the anode coating layer to suppress metal ion dissolution and induce anion trapping.

High-nickel cathode active materials have historically suffered from structural instability due to nickel ion dissolution. On the anode surface, side reactions with the electrolyte and uneven lithium deposition lead to dendrite formation, which limits battery lifespan.

This technology utilizes 2,2'-bipyridine-based COFs in the cathode to capture metal ions, create ion channels, and suppress nickel dissolution. Simultaneously, it forms a 2,2'-bipyridinium-based COF coating layer (AR-SEI) on the anode to trap anions and promote uniform lithium-ion flux. The manufacturing process is streamlined because the anode COF is derived from the quaternization of the cathode COF. Applicable to next-generation high-energy batteries using high-nickel cathodes and lithium metal anodes, this solution effectively addresses both cathode degradation and anode dendrites using a single material family.

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Key Features:

• A cathode active material layer formed on a current collector, containing a cathode active material and up to 5 wt% of a covalent organic framework.
• A hexagonal framework where the repeating unit of Chemical Formula 1 forms one side, featuring internal pores with diameters of 1.0 to 8.0 nm.
• A coating layer formed on a lithium metal anode substrate with a thickness of 1000 nm or less, containing 10 to 50 wt% of a covalent organic framework.
• A covalent organic framework where 2D sheets are vertically stacked at intervals of 10 nm or less to form a 3D mesoporous structure.

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This invention was developed with support from the Ministry of Science and ICT for a single-ion conductor-based multidimensional free-form power system.

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