以酚醛树脂为碳源原位合成富锂层状相/尖晶石/碳核壳结构正极材料及其电化学性能

通过酚醛树酯包覆和碳热反应在富锂正极材料表面原位构建碳和尖晶石双壳保护结构, 对这种核壳结构的正极材料进行了结构和形貌表征, 并研究了其电化学性能. 研究发现, 尖晶石相为材料提供了三维锂离子迁移通道, 碳包覆层显著提高了正极材料的电子电导率, 两种效应的共同作用极大降低了材料的电化学阻抗, 提升了材料的放电比容量, 这种多壳层结构正极材料还具有优异的倍率性能, 在5C倍率下放电比容量可达到135.1 mA·h/g.

Synthesis of Li-rich Layers/Spinel/Carbon Composite Cathode Materials with Phenol Formaldehyde Resin and Its Electrochemical Performance†

A li-rich layers/spinel/carbon heterostructure cathode material was synthesized by phenol formaldehyde resin coating and subsequent carbon thermal reaction, the structure, monography and electrochemical performance of the material were studied. For this structure, the spinel phase plays a role to provide a three-dimensional lithium-ion transport channel while the carbon coating layer help with the conductivity of the cathode. Those two layers lower the electrochemical impedance of the material and improve the specific capacity. The cathode material deliver an excellent performance of 135.1 mA·h/g at 5C.