丰富氧缺陷MnO_(x)掺杂的碳纳米纤维基锌离子电池阴极材料的制备及性能EI北大核心CSCD

可充电水系锌离子电池(ZIBs)由于性能优良、价格低廉、环境友好等优点而被广泛研究,而针对高容量、长循环寿命的ZIBs阴极结构设计成为该领域研究的热点。采用同轴静电纺丝法,以PAN溶液为皮层,含有Mn(NO_(3))_(2)·xH_(2)O的PAN溶液为芯层制备纳米纤维膜,并对其炭化后得到了一种表面具有类皮脂腺凸起结构的碳纳米纤维(MCNFs),在其表面电化学沉积MnO_(2),制得了与电解液具有优良亲和性的MnO_(2)@MCNFs阴极材料。研究表明:设计得到的类皮脂腺结构不仅增大了阴极比表面积,而且在MCNFs基底与电化学沉积的α-MnO_(2)活性物质之间形成铆接效应,加固了界面结合,减少活性物质脱落,降低界面电阻,缩短了电子传导和离子扩散路径。对其电化学性能进行测试,芯层Mn(NO_(3))_(2)·xH_(2)O含量为3%的阴极在100 mA/g的电流密度下,首周次比容量达581.16 mAh/g;在1 A/g电流密度下循环1000周次后比容量仍大于120 mAh/g,库仑效率保持在99%左右。

Preparation and properties of carbon nanofiberbased cathode materials for zinc-ion battery doped with rich oxygen deficiency MnOx

Rechargeable aqueous zinc-ion batteries (ZIBs) have been widely studied because of its excellent performance, low price and environment-friendly, and the structure design of ZIBs cathode with high capacity and long cycle life have become the focus. PAN solution containing Mn(NO₃)₂·xH₂O was used as a core layer and PAN solution as skin layer by coaxial electrospinning. Due to the concentration gradient diffusion, Mn(NO₃)₂·xH₂O diffused to the cortex. And MCNFs with sebaceous glandular structure on the surface was obtained by carbonization. MnO₂ was electrodeposited on its surface, and MnO₂@MCNFs cathode with excellent affinity with electrolytes were prepared. The results show that the sebaceous gland structure not only increases the specific surface area of cathode, but also constructs the riveting effect between MCNFs and α-MnO₂, which enhances the interface bonding between the substrate and the active material, reduces the shedding of α-MnO₂, reduces the interface resistance, and shortens the electron conduction and ion diffusion path. The test shows that the specific capacity of the first cycle of 3% MnO₂@MCNFs can reach about 581.16 mAh/g under the current density of 100 mA/g, and the specific capacity of 120 mAh/g can be maintained after 1000 cycles under the high current density of 1 A/g, and the coulomb efficiency is around 99%.