Karuppiah Saravanan, Keller Caroline, Kumar Praveen, Jouneau Pierre-Henri, Aldakov Dmitry, Ducros Jean-Baptiste, Lapertot Gérard, Chenevier Pascale, Haon Cédric
Université Grenoble Alpes, CEA, CNRS, IRIG, SYMMES, STEP, 38000 Grenoble, France.
Université Grenoble Alpes, CEA, LITEN, DEHT, 38000 Grenoble, France.
ACS Nano. 2020 Sep 22;14(9):12006-12015. doi: 10.1021/acsnano.0c05198. Epub 2020 Sep 14.
Silicon (Si) is the most promising anode candidate for the next generation of lithium-ion batteries but difficult to cycle due to its poor electronic conductivity and large volume change during cycling. Nanostructured Si-based materials allow high loading and cycling stability but remain a challenge for process and engineering. We prepare a Si nanowires-grown-on-graphite one-pot composite (Gt-SiNW) a simple and scalable route. The uniform distribution of SiNW and the graphite flakes alignment prevent electrode pulverization and accommodate volume expansion during cycling, resulting in very low electrode swelling. Our designed nanoarchitecture delivers outstanding electrochemical performance with a capacity retention of 87% after 250 cycles at 2C rate with an industrial electrode density of 1.6 g cm. Full cells with NMC-622 cathode display a capacity retention of 70% over 300 cycles. This work provides insights into the fruitful engineering of active composites at the nano- and microscales to design efficient Si-rich anodes.
硅(Si)是下一代锂离子电池最有前景的负极候选材料,但由于其电子导电性差和循环过程中体积变化大,难以实现循环使用。纳米结构的硅基材料具有高负载量和循环稳定性,但在工艺和工程方面仍面临挑战。我们通过一种简单且可扩展的路线制备了一种硅纳米线生长在石墨上的一锅法复合材料(Gt-SiNW)。硅纳米线的均匀分布和石墨薄片的排列可防止电极粉化,并在循环过程中适应体积膨胀,从而使电极膨胀非常低。我们设计的纳米结构具有出色的电化学性能,在2C倍率下以1.6 g/cm的工业电极密度循环250次后容量保持率为87%。采用NMC-622正极的全电池在300次循环中容量保持率为70%。这项工作为在纳米和微观尺度上对活性复合材料进行有效工程设计以制备高效富硅负极提供了思路。