Mg掺杂对LiNi_(0.6)Co_(0.15)Mn_(0.25)O_2电化学性能的影响

以氢氧化钠为沉淀剂,氨水为络合剂,通过氢氧化物共沉淀法制得前驱体,然后高温煅烧,合成锂离子电池正极材料Li(Ni_(0.6)Co_(0.15)Mn_(0.25))_(1-x)Mg_xO_2(x=0、0.01、0.02、0.03和0.04)。通过XRD、循环伏安、电化学阻抗谱(EIS)和恒流充放电等测试,研究Mg掺杂对材料性能的影响。适量的Mg掺杂可降低材料阳离子混排度,提高材料的循环性能及倍率性能。Li(Ni_(0.6)Co_(0.15)Mn_(0.25))_(0.98)Mg_(0.02)O_2的电化学性能较好,以0.1 C在2.7~4.3 V循环,首次放电比容量高达190.9 mAh/g;1.0 C循环30次的容量保持率为90.07%。

Effect of Mg doping on electrochemical performance of LiNi0.6Co0.15Mn0.25O2

The precursors were synthesized by hydroxide coprecipitation method using sodium hydroxide as precipitating agent and ammonia as complexing agent.Li(Ni0.6 Co0.15 Mn0.25) 1-x MgxO2 (x =0,0.01,0.02,0.03 and 0.04) cathode materials for Li-ion battery were synthesized by a high-temperature solid state method.The influence of Mg2 + doping on the performance of material was studied using XRD,cyclic voltammetry,electrochemical impedance spectra(EIS) and galvanostatic charge-discharge test.The cation mixing degree decreased after Mg doping,the cycle performance and the rate performance of the materials were improved.Li (Ni0.6 Co0.15 Mn0.25) 0.98 Mg0.02 O2 showed better electrochemical performance.It delivered a high initial discharge capacity of 190.9 mAh/g at 0.1 C rate in 2.7-4.3 V and the capacity retention was 90.07％ after 30 cycles at 1.0 C.