阳极
材料科学
微粒
锂(药物)
粒子(生态学)
压力(语言学)
纳米颗粒
离子
化学工程
硅
制作
纳米技术
热扩散率
复合材料
光电子学
化学
电极
热力学
替代医学
病理
物理
内分泌学
工程类
地质学
物理化学
有机化学
哲学
海洋学
语言学
医学
作者
Yao Gao,Fan Li,Rui Zhou,Xiaoqiong Du,Zengbao Jiao,Biao Zhang
标识
DOI:10.1007/s40820-023-01190-7
摘要
Abstract Si is a promising anode material for Li ion batteries because of its high specific capacity, abundant reserve, and low cost. However, its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process. The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles. Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles, which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process. The Si 8.5 Sn 0.5 Sb microparticles (mean particle size: 8.22 μm) show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles, respectively. The discharge capacities of the Si 8.5 Sn 0.5 Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g −1 are 1.62 and 1.19 Ah g −1 , respectively, corresponding to a retention rate of 94.2% and 99.6%, respectively, relative to the capacity of the first cycle after activation. Multicomponent microparticle anodes containing Si, Sn, Sb, Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02% per cycle for 1000 cycles at 1 A g −1 , corroborating the proposed mechanism. The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy–density Li-ion batteries.
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