Radical-trapping lithium battery anode

Abstract

The invention discloses a radical-trapping lithium battery anode. The lithium battery anode comprises a current collector, an anode active material, a conductive agent, and a binding agent. To reduceadverse effects of the generation of high-voltage lithium battery anode radicals on the cycling performance of a battery, nitroxyl radicals and other groups, which are introduced into a polymer molecule structure of the binding agent, can effectively trap the radicals generated by the anode, reduce the electrolyte composition, and form a stable anode interface layer on the anode to inhibit continued radical generation; the radical-trapping groups comprise the nitroxide radicals and derivatives thereof, phenol and derivatives thereof, benzenediol and derivatives thereof, and hydroxyquinol and derivatives thereof; and the polymer molecule structure comprises a natural polymer adhesive and a synthetic polymer adhesive.

Description

technical field [0001] The invention relates to a functionalized lithium battery positive electrode and a preparation method thereof, in particular to a positive electrode with free radical trapping function and a preparation method thereof. Background technique [0002] Rechargeable lithium-ion batteries have the advantages of high energy density, long cycle life, and low environmental pollution, and have been widely used in electric vehicle power equipment and small energy storage devices. Electric vehicles, power grid energy storage, etc. are increasingly demanding high operating voltage and high energy density lithium-ion batteries. Rechargeable lithium-ion batteries will produce more side reactions at high voltages, such as the dissolution of metal ions in positive active materials and corrosion of aluminum foil. , Oxidative decomposition of the electrolyte. Among them, the oxidative decomposition of the electrolyte will lead to a decrease in the electrolyte content in...

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Problems solved by technology

For example, the positive active material uses LiNi 0.5 mn 1.5 o 4 When the carbonate electrolyte is cycled at a high voltage, the carbonate solvent molecules form free radicals through proton-coupled electron transfer (J. Am. Chem. Soc., 2015, 137 (10), 3533-3539). The base consumes the electrolyte through further reactions, and the coordination between the reaction product and the metal ions in the positive active material leads to the dissolution of the transition metal in the positive active material and destroys the crystal structure of the active material. The above-mentioned side reactions will lead to the cycle of the battery performance degradation

[0003] The influence of free radicals is not considered in the existing methods for preparing the positive electrode of lithium batteries, and the generation of free radicals at the positive electrode of high-voltage lithium batteries will have an adverse effect on the cycle performance of the battery. Electrolyte contact can effectively reduce electrolyte decomposition, which is expected to improve battery performance

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