Preparation And Electrochemical Performance Of Nickel-rich Layered Cathode Material LiNi_0.8Co_0.1Mn_0.1O₂ For Lithium Ion Batteries

In recent years,the energy problem caused by the fossil fuels depletion,and environmental pollution caused by the fossil fuels burning,keep us looking for reasons and improving methods.It is generally believed that automobile exhaust is one of the main reasons of air pollution.Developing new energy electric vehicles can control automobile exhaust emissions and reduce fossil fuel use at the same time.Lithium ion battery are widely used in electric vehicles with high cut-off voltage,high energy density,good cycling performance,low self-discharge,and environmental friendliness.However,the development of electric vehicles primarily is limited by the short driving range which depends on the power battery's capacity.Cathode material plays an important role in the capacity of lithium-ion batteries.Nickel-rich LiNi_0.8Co_0.1Mn_0.1O₂ is considered as one of the most promising cathode materials in lithium-ion battery,and has attracted extensive attention for its over 200mAh·g^-11 specific capacity and environmental friendliness,which can achieve the national planning index of high capacity density..In this paper,LiNi_0.8Co_0.1Mn_0.1O₂ was used as the research object,and its controllable preparation was studied.The preparation conditions on the electrochemical performance,and the calendar storage performance,as well as the performance recovery of the material after storage were studied.The specific research was as follows:Firstly,we got spherical particles as precursors by strictly controllable co-precipitation method.Then,LiNi_0.8Co_0.1Mn_0.1O₂ preparation process such as calcination temperature,calcination atmosphere,sintering conditions,calcination time,was investigated to improve electrochemical performance.In addition,the high cut-off voltage?4.5V?impact on the charge-discharge performance of LiNi_0.8Co_0.1Mn_0.1O₂ was also tested.Under 2.7-4.3V and2.7-4.5V,The material exhibits good electrochemical performance with the initial discharge specific capacity of 193.7mAh·g^-1,200.1mAh·g^-11 at 0.1C and the maximum discharge specific capacity of 183.4mAh·g^-1,188.6mAh·g^-11 at 1C,respectively.On this basis,the LiNi_0.8Co_0.1Mn_0.1O₂ materials was stored under different conditions to study the effect of time,temperature and humidity on the calendar storage performance of this material.The results show that in the dryer,the storage of 20 natural days will not have a significant impact on the performance of LiNi_0.8Co_0.1Mn_0.1O₂;placed under high temperature will affect the material cycle performance;and the higher humidity,the greater the impact on the material,under high humidity,the material surface phase will change.Finally,the performance of the material after storage is recovered.The charge/discharge capacity of the first cycle under 2.7-4.3V cut-off voltage is225.4/193.8mAh·g^-11 in 0.1C,and the performance is greatly improved compared with the stored material.The optimum preparation conditions and storage conditions of the materials were given in this paper,which provides a new method for the preparation and calendar storage of LiNi_0.8Co_0.1Mn_0.1O₂ material.The research on the recovery of the material after stored reduces the influence of the storage,which provides a new idea for the researche and development of LiNi_0.8Co_0.1Mn_0.1O₂ material.