采用液相无焰燃烧法在500℃反应1 h、600℃二次焙烧不同时间制备锂、镍共掺杂尖晶石型Li_1.05Ni_0.02Mn_1.93O₄正极材料。焙烧不同时间制备的样品均呈现出LiMn₂O₄的尖晶石晶体结构且均为单相，没有任何杂质相出现。延长焙烧时间有利于晶粒发育，提高合成材料的结晶性。二次焙烧9 h合成的正极材料具有良好的循环稳定性和倍率性能，在1 C倍率的首次放电容量为102.1 mA·h/g，500次循环后具有69.15%的容量保持率；在5 C释放出91.9 mA·h/g容量；10 C循环1 000次的容量保持率为76.35%。具有较好的循环可逆性、较小的电荷转移阻抗和较低的表观活化能。适量的锂、镍共掺杂可有效提高LiMn₂O₄的结构稳定性、抑制Jahn-Teller效应和缓解锰的溶解，使其具有更高的电化学性能。

Li-Ni co-doped Li_1.05Ni_0.02Mn_1.93O₄ cathode materials are synthesized via a liquid phase flameless combustion method at 500℃ for 1 h, followed by calcination at 600℃ for various lengths of time.All the as-prepared samples correspond to the spinel crystal structure of LiMn₂O₄ with a single-phase, without any impurity phase.With longer calcination time, the particle size is increased and the crystallinity is enhanced.The sample synthesized for 9 h of calcination has an excellent cycle stability and rate performance, delivers an initial discharge capacity of 102.1 mAh·g^-1 and maintains a capacity retention of 69.15% after 500 cycles at 1 C.The initial discharge capacity is 91.9 mAh·g^-1 at 5 C, and the capacity retention is 76.35% at 10 C after 1 000 cycles.The optimized electrode has a good cycling reversibility, a small charge transfer impedance and a low apparent activation energy.Appropriate Li, Ni ions dual-doping can effectively improve the structural stability of spinel LiMn₂O₄, inhibit the Jahn-Teller effect and relieve the dissolution of Mn, hence improving electrochemical performance.

李豫云(1996-),女,硕士研究生,研究方向为锂硫电池正极材料,liyu-yun@163.com。