Yang Chaofan, Qiao Chong, Chen Yang, Zhao Xueqi, Wu Lulu, Li Yong, Jia Yu, Wang Songyou, Cui Xiaoli
Department of Materials Science, Fudan University, Shanghai, 200433, China.
Shanghai Ultra-Precision Optical Manufacturing Engineering Center and Department of Optical Science and Engineering, Fudan University, Shanghai, 200433, China.
Small. 2020 Mar;16(10):e1907365. doi: 10.1002/smll.201907365. Epub 2020 Feb 13.
High energy density is the major demand for next-generation rechargeable batteries, while the intrinsic low alkali metal adsorption of traditional carbon-based electrode remains the main challenge. Here, the mechanochemical route is proposed to prepare nitrogen doped γ-graphyne (NGY) and its high capacity is demonstrated in lithium (LIBs)/sodium (SIBs) ion batteries. The sample delivers large reversible Li (1037 mAh g ) and Na (570.4 mAh g ) storage capacities at 100 mA g and presents excellent rate capabilities (526 mAh g for LIBs and 180.2 mAh g for SIBs) at 5 A g . The superior Li/Na storage mechanisms of NGY are revealed by its 2D morphology evolution, quantitative kinetics, and theoretical calculations. The effects on the diffusion barriers (E ) and adsorption energies (E ) of Li/Na atoms in NGY are also studied and imine-N is demonstrated to be the ideal doping format to enhance the Li/Na storage performance. Besides, the Li/Na adsorption routes in NGY are optimized according to the experimental and the first-principles calculation results. This work provides a facile way to fabricate high capacity electrodes in LIBs/SIBs, which is also instructive for the design of other heteroatomic doped electrodes.
高能量密度是下一代可充电电池的主要需求,而传统碳基电极固有的低碱金属吸附性仍然是主要挑战。在此,提出了机械化学路线来制备氮掺杂的γ-石墨炔(NGY),并在锂(LIBs)/钠(SIBs)离子电池中展示了其高容量。该样品在100 mA g下具有较大的可逆锂(1037 mAh g)和钠(570.4 mAh g)存储容量,在5 A g下表现出优异的倍率性能(LIBs为526 mAh g,SIBs为180.2 mAh g)。通过其二维形态演变、定量动力学和理论计算揭示了NGY优异的锂/钠存储机制。还研究了对NGY中锂/钠原子扩散势垒(E)和吸附能(E)的影响,并证明亚胺-N是增强锂/钠存储性能的理想掺杂形式。此外,根据实验和第一性原理计算结果优化了NGY中的锂/钠吸附途径。这项工作为在LIBs/SIBs中制备高容量电极提供了一种简便方法,对其他杂原子掺杂电极的设计也具有指导意义。