聚(3-己基噻吩)包覆富锂层状正极材料Li_(1.18)Ni_(0.15)Co_(0.15)Mn_(0.52)O_2的制备与电化学性能

Preparation and Electrochemical Properties of Poly(3-hexylthiophene)-coated Lithium-rich Layered Cathode Material Li_(1.18)Ni_(0.15)Co_(0.15)Mn_(0.52)O_2

采用溶胶-凝胶法合成了Li_(1.18)Ni_(0.15)Co_(0.15)Mn_(0.52)O_2富锂层状正极材料,并使用聚(3-己基噻吩)对其进行了表面包覆.采用多种光谱学和电化学手段对材料的形貌结构和电化学性能进行了分析.结果表明,聚(3-己基噻吩)溶液浸泡后在富锂材料表面形成厚约1. 5 nm的均匀包覆层.表面包覆后富锂层状正极材料的极化和阻抗明显减小.在0. 2C倍率下,经过100次充放电循环后,未包覆的富锂材料放电比容量衰减为170 m A·h/g,而经过0. 3%聚(3-己基噻吩)包覆的材料的放电比容量则保持在205 m A·h/g,容量保持率由68%提高到82%; 10C倍率下的放电比容量由72 m A·h/g提高到116 m A·h/g.

Lithium-rich layered cathode material Li1.18Ni0.15Co0.15Mn0.52O2 was synthesized by sol-gel method and then coated with poly(3-hexylthiophene).Varies spectroscopic and electrochemical techniques were used to analyze the morphology and electrochemical properties of the materials.The results showed that a homogeneous coating layer with a thickness of ca.1.5 nm was formed on the surface of the material.The electrode polarization and impedance of the material were obviously reduced by surface coating.After 100 cycles at0.2 C,the specific capacity of the original material decreased to 170 m A·h/g,while that of the 0.3%poly(3-hexylthiophene)coated material still remained at 205 m A·h/g.The corresponding capacity retention increased from 68%to 82%.Moreover,the discharge capacity at 10 C rate increased from 72 m A·h/g to116 m A·h/g.