Metal oxide lithium ionic cell positive pole material and preparation thereof

Abstract

The invention discloses a metal oxide lithium ion battery positive material and a preparation method thereof. The problem to be solved is to improve the electrochemistry property of the positive material. The material formula of the invention is LiNi1-x-y-zMnxCoyMzO2, wherein the x+y+z is less than 1, or a quaternary or a quinary metal oxide material of the LiNi1-x-y-z-rMnxCoyMzNrO2, wherein the x+y+z+r is less than 1, and the M and N are selected from one of the Al, Ti, Cr, Mg, V, Zn and Zr, x is equal to 0.01-0.8, y is equal to 0.01-0.8, z is equal to 0.01-0.8 and r is equal to 0.01-0.8. The preparation method comprises: preparing a precursor mixture, mixing and sintering. Comparing with the prior art, the invention prepares the oxide lithium ion battery material by a liquid phase multi-element mixing reaction, a mixing method and a solid state sintering method, the maximum discharging capacity is larger than 150mAh / g, the primary coulomb efficiency is more than 90, the capacity conservation rate after 300 cycles is more than 95 The metal oxide lithium ion battery positive material is suitable for industrial scale production.

Description

technical field [0001] The invention relates to a lithium ion battery cathode material and a preparation method thereof, in particular to a four- or five-element metal oxide lithium ion battery cathode material and a preparation method thereof. Background technique [0002] Since Sony successfully realized the commercial production of lithium-ion secondary batteries in the 1990s, because lithium-ion batteries have high working voltage, high specific energy, light weight, small size, long cycle life, no memory effect, fast charge and discharge and A series of significant advantages such as no environmental pollution, and become the preferred power supply of portable electronic appliances such as cameras, mobile phones, notebook computers, portable measuring instruments, etc., and are also widely used in various portable electronic products and mobile tools. There are also huge application prospects in automotive EV and hybrid electric vehicle HEV power supplies. The cathode ...

AI Technical Summary

Problems solved by technology

LiCoO 2 Due to relatively high cost and relatively low capacity, the theoretical capacity is as high as 274mAh / g, but its actual capacity is only 130-140mAh / g, and the safety of overcharging limits its development space; LiNiO 2 It has a relatively high capacity, but poor thermal stability, and the capacity decays significantly when charging and discharging under high current; LiMnO 2 The electrode capacity is relatively large, but the structure is unstable in the cycle, and it is easy to transform to spinel type, resulting in capacity decay; LiMn 2 o 4 The synthesis is simple, the price is low, and the safety performance is good, but its discharge capacity is low, about 120mAh / g. Secondly, the Jahn-Teller distortion effect will occur during the charge and discharge process, resulting in deformation of the material structure when the temperature is higher than 55 ° C. , the generated Mn 2 + Dissolving in the electrolyte causes the electrode active material to lose, and the capacity fades quickly, which hinders the LiMn 2 o 4 Application of Cathode Materials

Phosphate series materials are low in cost and environmentally friendly, but their poor electrical conductivity leads to poor cycle performance, which ultimately affects their commercial applications

The positive electrode materials of the above three systems have their own advantages and disadvantages, which cannot meet the development needs of lithium-ion batteries in the future.

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