Positive electrode lithium supplementing material and preparation method and application thereof

The invention relates to the technical field of lithium ion batteries, in particular to a positive electrode lithium supplementing material and a preparation method and application thereof. The lithium squarate and the positive electrode material are mixed through a ball milling method to prepare the positive electrode lithium supplementing material, the positive electrode material serving as a catalyst can promote complete decomposition of the lithium squarate, the capacity of the lithium squarate can be completely released, adverse effects on the positive electrode are reduced, the energy density of the battery is greatly improved, and the cycle life of the battery is greatly prolonged. And the first charging and discharging capacity of the battery is increased, so that the performance of the lithium ion battery is optimized. The positive electrode lithium supplementing material is applied to a positive plate in a battery, can simply and efficiently achieve the purpose of supplementing lithium to a positive