A kind of positive electrode lithium supplement material and preparation method and application thereof

Abstract

The invention provides a positive electrode lithium supplement material and its preparation method and application, the positive electrode lithium supplement material comprises Li 2‑x Ni 1‑ y m y o 2 and coated in Li 2‑x Ni 1‑y m y o 2 Surface Me m o n A cladding layer; wherein the M includes any one or a combination of at least two of Cu, Fe or V, and the Me includes any one or a combination of at least two of Ti, Al, Zr or B, the present invention The invention uses low-cost metal elements for precursor co-precipitation doping, which can replace part of Ni while reducing costs 2+ , reduce lithium-nickel mixing, and stabilize the structure during the cycle of the cell, reduce the amount of oxygen released, in the Li 2‑x Ni 1‑ y m y o 2 Me m o n The coating layer greatly reduces the amount of residual lithium in the finished product, improves processing and gas production performance, and at the same time can inhibit the dissolution of transition metals nickel, copper, and iron, and the anode damages the SEI film, thereby improving the cycle.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and relates to a positive electrode lithium supplement material and a preparation method and application thereof. Background technique [0002] Lithium-ion batteries have the advantages of high voltage, high specific energy, and good safety performance, and have been widely used in portable electronic products and electric vehicles. With the rapid development of new energy vehicles, smart grids, and distributed energy storage, higher requirements have been placed on the energy density of new energy devices, and there is an urgent need to study high-capacity electrode materials. High-capacity electrode materials are often accompanied by low first efficiency. During the first charge and discharge of lithium-ion batteries, with the formation of SEI films on the surfaces of positive and negative electrodes, the limited number of active lithium ions in the battery will inevitably be consumed. As ...

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Problems solved by technology

But at the same time, it also caused the residue of non-lithium source components in the lithium supplement material, leaving more impurities, causing serious self-discharge of the battery cell, and a decrease in the discharge capacity.

[0005] In CN1290209C, it is reported that lithium metal, negative electrode material and non-aqueous liquid are mixed to form a slurry, the slurry is coated on the negative electrode current collector, and the dry slurry is prepared into a battery. Although this method can improve the initial efficiency, due to the high reaction rate of lithium metal Activity, the entire operation needs to be carried out in an anhydrous and dry environment, resulting in difficult operation and high equipment cost

[0006] The above solutions have problems such as low capacity, high cost, or low efficiency. Therefore, it is urgent to develop a lithium-supplementing material with high capacity, low cost, and high battery efficiency for application in lithium-ion batteries.

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