Li Jiaxin, Huang Yongcong, Huang Weijian, Tao Jianming, Lv Fucong, Ye Ruilai, Lin Yingbin, Li Yang Yang, Huang Zhigao, Lu Jian
College of Physics and Energy, Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, Fujian Normal University, Fuzhou, 350117, China.
Department of Physics and Materials Science, Hong Kong Branch of National Precious Metals Material Engineering Research Centre, City University of Hong Kong, Hong Kong, 999077, China.
Small. 2021 Feb;17(8):e2006373. doi: 10.1002/smll.202006373. Epub 2021 Feb 1.
Up to now, the silicon-graphite anode materials with commercial prospect for lithium batteries (LIBs) still face three dilemmas of the huge volume effect, the poor interface compatibility, and the high resistance. To address the above challenges, micro-nano structured composites of graphite coating by ZnO-incorporated and carbon-coated silicon (marked as Gr@ZnO-Si-C) are reasonably synthesized via an efficient and convenient method of liquid phase self-assembly synthesis combined with annealing treatment. The designed composites of Gr@ZnO-Si-C deliver excellent lithium battery performance with good rate performance and stable long-cycling life of 1000 cycles with reversible capacities of 1150 and 780 mAh g tested at 600 and 1200 mA g , respectively. The obtained results reveal that the incorporated ZnO effectively improve the interface compatibility between electrolyte and active materials, and boost the formation of compact and stable surface solid electrolyte interphase layer for electrodes. Furthermore, the pyrolytic carbon layer formed from polyacrylamide can directly improve electrical conductivity, decrease polarization, and thus promote their electrochemical performance. Finally, based on the scalable preparation of Gr@ZnO-Si-C composites, the pouch full cells of Gr@ZnO-Si-C||NCM523 are assembled and used to evaluate the commercial prospects of Si-graphite composites, offering highly useful information for researchers working in the battery industry.
到目前为止,具有商业前景的锂电池硅石墨负极材料仍面临巨大体积效应、较差的界面兼容性和高电阻这三大困境。为应对上述挑战,通过液相自组装合成与退火处理相结合的高效便捷方法,合理合成了氧化锌掺杂包覆碳的硅微纳结构复合材料(标记为Gr@ZnO-Si-C)。所设计的Gr@ZnO-Si-C复合材料展现出优异的锂电池性能,具有良好的倍率性能以及1000次循环的稳定长循环寿命,在600和1200 mA g下测试的可逆容量分别为1150和780 mAh g。所得结果表明,掺入的氧化锌有效改善了电解质与活性材料之间的界面兼容性,并促进了电极致密且稳定的表面固体电解质中间相层的形成。此外,由聚丙烯酰胺形成的热解碳层可直接提高电导率、降低极化,从而提升其电化学性能。最后,基于Gr@ZnO-Si-C复合材料的可扩展制备,组装了Gr@ZnO-Si-C||NCM523软包全电池,用于评估硅石墨复合材料的商业前景,为电池行业的研究人员提供了非常有用的信息。