前驱体合成温度对高镍正极LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)性能的影响

Influence of hydroxide precursors'synthesizing temperature on performance of Ni-rich LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)cathode

高镍正极材料具备高的能量密度和低的原料成本,被认为是极具前景的动力电池材料。高镍正极材料的容量和循环性能非常依赖于其氢氧化物前驱体的物化性能。但是,正极材料与对应前驱体的关联性研究相对较少。报道了LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)前驱体的合成温度(50~70℃)对前驱体物化性能及对应正极材料的总体性能的影响。测试结果证明前驱体的共沉淀温度为60℃时,对应的LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)正极材料具备好的结晶度和均匀的一次晶粒分布,表现出最优异的电化学性能,0.1 C下该高镍正极材料表现出217 mAh/g的初始放电比容量,1 C下循环50圈的容量保持率为93.1%。同时,该温度下制备的前驱体对应的正极材料具备优异的热稳定性,其放热峰值温度为212.5℃,放热量为1574 J/g。该研究证明了前驱体合成温度对正极材料性能的影响,为高镍正极材料工艺优化提供了指导性意见。

Ni-rich cathode materials with high energy density are considered as promising candidates for electric vehicles.The capacity and cycling ability of Ni-rich cathode materials depend exceedingly on the physicochemical properties of hydroxide precursors.However,insufficient endeavors were made to study the impact of precursors on the quality of Ni-rich cathode materials.Herein,a set of studies on the relationship between hydroxide co-precipitation temperature(50~70 ℃)and the general performance of corresponding LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)cathode materials were reported.It’s demonstrated that the synthesis temperature of hydroxide precursors play an important role in electrochemical performances of LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)cathode materials.The LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)cathode shows remarkably excellent performances under the synthesis temperature of 60 ℃ for hydroxide precursors.Accordingly,this material delivers admirable initial reversible capacity(217 mAh/g at 0.1 C),cycling stability(93.1%retention ratio after 50 cycles at 1 C)and thermal stability(the exothermic peak temperature is 212.5℃and the heat release is 1574 J/g).The research provides a simple,efficient,and scalable method to elevate the performance of Ni-rich LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)cathode and paves the way for industrial application.