Keller Caroline, Desrues Antoine, Karuppiah Saravanan, Martin Eléa, Alper John P, Boismain Florent, Villevieille Claire, Herlin-Boime Nathalie, Haon Cédric, Chenevier Pascale
CEA, CNRS, IRIG, SYMMES, STEP, University Grenoble Alpes, 38000 Grenoble, France.
CEA, LITEN, DEHT, University Grenoble Alpes, 38000 Grenoble, France.
Nanomaterials (Basel). 2021 Jan 25;11(2):307. doi: 10.3390/nano11020307.
Silicon is a promising material for high-energy anode materials for the next generation of lithium-ion batteries. The gain in specific capacity depends highly on the quality of the Si dispersion and on the size and shape of the nano-silicon. The aim of this study is to investigate the impact of the size/shape of Si on the electrochemical performance of conventional Li-ion batteries. The scalable synthesis processes of both nanoparticles and nanowires in the 10-100 nm size range are discussed. In cycling lithium batteries, the initial specific capacity is significantly higher for nanoparticles than for nanowires. We demonstrate a linear correlation of the first Coulombic efficiency with the specific area of the Si materials. In long-term cycling tests, the electrochemical performance of the nanoparticles fades faster due to an increased internal resistance, whereas the smallest nanowires show an impressive cycling stability. Finally, the reversibility of the electrochemical processes is found to be highly dependent on the size/shape of the Si particles and its impact on lithiation depth, formation of crystalline LiSi in cycling, and Li transport pathways.
硅是下一代锂离子电池高能负极材料的一种很有前景的材料。比容量的增加高度依赖于硅分散体的质量以及纳米硅的尺寸和形状。本研究的目的是研究硅的尺寸/形状对传统锂离子电池电化学性能的影响。讨论了尺寸在10 - 100纳米范围内的纳米颗粒和纳米线的可扩展合成工艺。在循环锂电池中，纳米颗粒的初始比容量明显高于纳米线。我们证明了首次库仑效率与硅材料比表面积之间存在线性关系。在长期循环测试中，由于内阻增加，纳米颗粒的电化学性能衰减更快，而最小的纳米线表现出令人印象深刻的循环稳定性。最后，发现电化学过程的可逆性高度依赖于硅颗粒的尺寸/形状及其对锂化深度、循环过程中结晶LiSi的形成以及锂传输路径的影响。
