Enhanced elevated-temperature performance of LiAl_xSi_0.05Mg_0.05Mn_1.90-xO₄ (0≤x≿.08) cathode materials for high-performance lithium-ion batteries

详细信息    查看全文

• 作者：Hongyuan Zhao^a ; ^b ; ^{huz9@psu.edu" class="auth_mail" title="E-mail the corresponding author} ; ^{hongyuanzhao@126.com" class="auth_mail" title="E-mail the corresponding author} ; Shanshan Liu^a ; Zhenwei Wang^a ; Yu Cai^a ; Ming Tan^a ; Xingquan Liu^a ; ^{Lxquan@uestc.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Lithium-ion battery ; Lithium manganese spinel ; Multi-cations doping ; Cycling stability ; Rate capability
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：1 May 2016
• 年：2016
• 卷：199
• 期：Complete
• 页码：18-26
• 全文大小：3393 K

文摘

In order to significantly enhance the elevated-temperature performance of LiSi_0.05Mg_0.05Mn_1.90O₄, the LiAl_xSi_0.05Mg_0.05Mn_1.90-xO₄ (0 ≤ x ≤ 0.08) samples were firstly prepared via sol-gel technique. All the obtained samples showed the intrinsic spinel structure without any other detectable impurity phases. Among these samples, the LiAl_0.05Si_0.05Mg_0.05Mn_1.85O₄ sample was found to be optimal possessing regular crystal morphology with clean surfaces and presented much better elevated-temperature cycling stability and rate capability. When carried out at 55 °C, the LiAl_0.05Si_0.05Mg_0.05Mn_1.85O₄ sample exhibited the initial discharge capacity of 123.6 mAh g⁻¹ at 0.5C between 3.20 and 4.35 V. After 100 cycles, the discharge capacity could still reach up to 115.9 mAh g⁻¹ with capacity retention of 93.8%, which was much higher than that of LiSi_0.05Mg_0.05Mn_1.90O₄. At the higher discharge rate of 10C, a high discharge capacity of 82.5 mAh g⁻¹ could be obtained with capacity retention of 95.6% after 50 cycles at 55 °C. By contrast, the LiSi_0.05Mg_0.05Mn_1.90O₄ sample only exhibited 43.7 mAh g⁻¹ with lower capacity retention of 61.8%. These results indicate that the introduction of appropriate amount of aluminium ions in the magnesium and silicon co-doped spinel can make up for the shortage of co-doping with magnesium and silicon ions in term of the elevated-temperature performance.