Effect of Metal (Mn, Ti) Doping on NCA Cathode Materials for Lithium Ion Batteries
Effect of Metal (Mn, Ti) Doping on NCA Cathode Materials for Lithium Ion Batteries
复制标题
DOI：
10.1155/2018/8082502
复制
发表时间：
2018-01
影响因子：
--
通讯作者：
D. Wan;Z. Fan;Yongrong Dong;Erdenebayar Baasanjav;H. Jun;B. Jin;E. Jin;S. Jeong
中科院分区：
文献类型：
--
作者：
D. Wan;Z. Fan;Yongrong Dong;Erdenebayar Baasanjav;H. Jun;B. Jin;E. Jin;S. Jeong
采用水热法在170°C下制备了NCA（LiNi 0.85Co 0.10Al 0.05-x MxO 2，M=Mn或Ti，< 0.01）正极材料，并对其进行了Mn和Ti掺杂以改善其电化学性能。采用XRD、FE-SEM和粒度分析等手段对不同NCA正极材料的晶相和形貌进行了表征。采用CV、EIS和恒电流充放电测试来确定阴极材料的电化学性能。Mn和Ti掺杂导致晶胞体积膨胀。该较大的体积还改善了阴极材料的电化学性质，因为Mn 4+和Ti 4+被引入到由Li离子占据的八面体晶格空间中以扩大Li层间距，从而改善了锂扩散动力学。结果，NCA-Ti电极表现出优异的上级性能，第一次循环后的高放电容量为179.6 mAh g-1，比未掺杂的NCA电极高几乎23 mAh g-1，30次循环后为166.7 mAh g-1。基于首次充放电容量的计算，观察到NCA-Ti电极的88.6%的良好库仑效率。此外，NCA-Ti阴极材料表现出最佳的循环稳定性，高达93%，长达30个循环。
NCA (LiNi0.85Co0.10Al0.05-x MxO2, M=Mn or Ti, < 0.01) cathode materials are prepared by a hydrothermal reaction at 170°C and doped with Mn and Ti to improve their electrochemical properties. The crystalline phases and morphologies of various NCA cathode materials are characterized by XRD, FE-SEM, and particle size distribution analysis. The CV, EIS, and galvanostatic charge/discharge test are employed to determine the electrochemical properties of the cathode materials. Mn and Ti doping resulted in cell volume expansion. This larger volume also improved the electrochemical properties of the cathode materials because Mn4+ and Ti4+ were introduced into the octahedral lattice space occupied by the Li-ions to expand the Li layer spacing and, thereby, improved the lithium diffusion kinetics. As a result, the NCA-Ti electrode exhibited superior performance with a high discharge capacity of 179.6 mAh g−1 after the first cycle, almost 23 mAh g−1 higher than that obtained with the undoped NCA electrode, and 166.7 mAh g−1 after 30 cycles. A good coulombic efficiency of 88.6% for the NCA-Ti electrode is observed based on calculations in the first charge and discharge capacities. In addition, the NCA-Ti cathode material exhibited the best cycling stability of 93% up to 30 cycles.