海藻酸辅助合成5V正极材料LiNi_(0.5)Mn_(1.5)O_4

Alginic Acid-Assisted Synthesis of Li Ni_(0.5)Mn_(1.5)O_4 Cathode Materials for 5V Lithium Batteries

首次利用海藻酸为模板剂,辅助合成了Fd3m空间群结构的锂电正极材料Li Ni0.5Mn1.5O4,同时分析了其结构、形貌及电化学性能等.与普通共沉淀法相比,海藻酸辅助制备的样品表现出了良好的形貌特征和电化学性能.X射线衍射(XRD)和扫描电子显微镜(SEM)观察的结果表明:制备的材料结晶度较高,颗粒晶型完整并达到微-纳级别.充放电测试结果表明:0.2C第一次放电表现出127.8 m Ah/g的比容量,且50次循环保持率在99%以上.同时,循环伏安(CV)和交流阻抗(EIS)测试结果可很好的解释其容量较高的原因.

In this paper, alginic acid is used, for the first time, as a template agent in the synthesis of the cathode material LiNi0.5Mnl.5O4 for lithium ion batteries. The structures, morphology as well as the electrochemical properties are characterized by a series of methods. The product synthesized using alginic acid-assisted method exhibits better morphology and electrochemical properties than its counterpart from conventional coprecipitation route. Results from X-ray diffraction and scanning electro-microscopy show that the products possess high crystalline degree and the particle sizes are in the range of micro-nano level. The coin cell comprise this material can exhibit an initial discharge capacity of 127.8 mAh/g at 0. 2C, and the capacity retention is over 99% after 50 cycles. Results from cyclic vohammetry and electrochemical impedance spectroscopy can well explain the superior capacity performance obtained.