Hu Hanbin, Li Haoyi, Zhang Zhenghe, Chen Wei, Wang Jikang, Lian Lifei, Yang Weimin, He Lei, Song Yu-Fei
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
Quzhou Institute for Innovation in Resource Chemical Engineering, Quzhou, Zhejiang 324000, P. R. China.
ACS Appl Mater Interfaces. 2023 Oct 4;15(39):45725-45731. doi: 10.1021/acsami.3c03663. Epub 2023 Sep 19.
Fast electron/ion transport and cycling stability of anode materials are key factors for achieving a high rate performance of battery materials. Herein, we successfully fabricated a carbon-coated MoC nanofiber (denoted as laser MoC@C) as the lithium ion battery anode material by laser carbonization of PAN-PMo (PAN = Polyacrylonitrile; PMo = HPMoO). The highly graphitized carbon layer in laser MoC@C effectively protects MoC from agglomeration and flaking while facilitating electron transfer. As such, the laser MoC@C electrode displays an excellent electrochemical stability under 5 A g, with a capacity up to 300 mA h g after 3000 cycles. Furthermore, the extended X-ray absorption fine structure results show the existence of some Mo vacancies in MoC@C. Density functional theory calculations further prove that such vacancies make the defective MoC@C composites energetically more favorable for lithium storage in comparison with the intact MoC.
阳极材料的快速电子/离子传输和循环稳定性是实现电池材料高倍率性能的关键因素。在此，我们通过对PAN-PMo（PAN = 聚丙烯腈；PMo = 磷钼酸）进行激光碳化，成功制备了一种碳包覆的MoC纳米纤维（记为激光MoC@C）作为锂离子电池阳极材料。激光MoC@C中高度石墨化的碳层有效保护MoC不发生团聚和剥落，同时促进电子转移。因此，激光MoC@C电极在5 A g的电流密度下表现出优异的电化学稳定性，经过3000次循环后容量高达300 mA h g。此外，扩展X射线吸收精细结构结果表明MoC@C中存在一些Mo空位。密度泛函理论计算进一步证明，与完整的MoC相比，这些空位使有缺陷的MoC@C复合材料在储锂方面在能量上更有利。
