空气中合成LiNi_(1-x)Al_xO_2的条件及其对结构的影响

Synthesis Conditions and Effects on Structure of LiNi_(1-x)Al_(x)O_(2) as Cathode for Li-ion Batteries

以Ni(OH)2,Al(OH)3和LiOH·H2O为原料,采用高温固相反应法在空气中合成了锂离子电池正极材料LiNi1-xAlxO2(x=0 025～0 30),用XRD研究了合成材料的物相和结构.研究了合成温度、合成时间、补锂量以及掺铝量对合成产物结构的影响.实验表明,掺铝有利于形成和稳定α NaFeO2型层状有序结构.随着掺铝量的增加,晶胞参数a0逐渐减小,而c0则逐渐增大.在空气中合成LiNi1-xAlxO2的最佳温度为750℃,合成时间以18～24h为宜,补锂量为10%(摩尔分数)效果较好.

LiNi_(1-x)Al_(x)O_(2)(x=0.025～0.30)is synthesized in air by solid reaction with Ni(OH)_(2), Al(OH)_(3 )and LiOH·H_(2)O as starting materials. The crystal structure is characterized by XRD. The effects of synthesis temperature, time, excess lithium and aluminum contents on the crystal structure are analysed.Experiment results show that substitution of aluminum for nickel in LiNiO_(2) is good for the formation and stabilization of layered α-NaFeO_(2) structure. With the increase of substituted aluminum,a_(0 ) decreased and c_(0 ) increased,the optimized condition for synthesis of LiNi_(1-x)Al_(x)O_(2) in air is to calcine at 750 ℃ for 18～24 h with 10 mol%(mole fraction) lithium excess.