【摘要】 本文采用两步烧结高温固相法成功制备了锡掺杂LiNi_0.5Mn_1.5-xSn_xO₄（0≤x≤0.1）锂离子电池正极材料.x为0.02时,LiNi_0.5Mn_1.48Sn_0.02O₄的比容量和循环性能最好.室温下,在3.5-4.9V电压范围内,0.1 C放电倍率,LiNi_0.5Mn_1.48Sn_0.02O₄的首次放电比容量为117mA h g^-1,而没有锡掺杂的LiNi_0.5Mn_1.5O₄只有101 mA h g^-1.此外,1 C放电100个循环后,所有锡掺杂后的LiNi_0.5Mn_1.5O₄材料均保持了较高的放电比容量;尤其是LiNi_0.5Mn_1.48Sn_0.02O₄,100个循环后,放电比容量为90 mA h g^-1,而纯的LiNi_0.5Mn_1.5O₄,100个循环后其放电比容量仅为56.1 mA h g^-1.锡掺杂后的LiNi_0.5Mn_1.48Sn_0.02O₄材料具有比LiNi_0.5Mn_1.5O₄材料及其他组材料更高的锂离子扩散效率,Sn离子的掺杂有利于锂离子的扩散和导电性的提高,从而提高了LiNi_0.5Mn_1.5O₄的电化学性能.因此锡掺杂是一种有效的改善高电压锂离子电池材料LiNi_0.5Mn_1.5O₄电化学性能的方法.更多还原

【Abstract】 LiNi_0.5Mn_1.5-xSn_xO₄（0≤ x ≤ 0.1） cathode materials with uniform and fine particle sizes were successfully synthesized by a two-step calcination of solid-state reaction method.As the cathode materials for lithium ion batteries,the LiNi_0.5Mn_1.48Sn_0.02O₄ shows the highest specific capacity and cycle stability.In the potential range of 3.5-4.9 V at room temperature,LiNi_0.5Mn_1.48Sn_0.02O₄ composite material shows a discharge capacity of more than 117 mA h g^-1 at0.1 C,while the corresponding discharge capacity of undoped LiNi_0.5Mn_1.5O₄ is only 101 mA h g^-1.Moreover,in cycle performance,all the LiNi_0.5Mn_1.5-xSn_xO₄（0≤ x≤ 0.1）samples show better capacity retention than the undoped LiNi_0.5Mn_1.5O₄ at 1 C rate after 100 cycles.Especially,for the LiNi_0.5Mn_1.5O₄,the discharge capacity after 100 cycles is90 mA h g^-1,while the corresponding discharge capacities of the undoped LiNi_0.5Mn_1.5O₄ is only 56.1 mA h g^-1.The significantly enhanced D_Li⁺ and the enlarged electronic conductivity make the Sn-doped spinel LiNi_0.5Mn_1.5O₄ material present even more excellent electrochemical performances.These results reveal that Sn-doping is an effective way to improve electrochemical performances of LiNi_0.5Mn_1.5O₄.更多还原