法拉第效率
电解质
材料科学
阳极
锂(药物)
硅
离子
化学工程
纳米技术
球磨机
无机化学
化学
工程类
有机化学
医学
内分泌学
作者
Wei Wu,Man Wang,Ruo Wang,Dongwei Xu,Hongbo Zeng,Chaoyang Wang,Yuliang Cao,Yonghong Deng
标识
DOI:10.1016/j.jpowsour.2018.10.065
摘要
Abstract SiOx has emerged as an important alternative to silicon as the high capacity anode host to store lithium due to its smaller volume change upon lithiation. However, conventional synthesis methods generally require harsh reaction conditions, making its production in industrial scale much challenging. Herein, a safe, economical and scalable approach is developed for SiOx using highly abundant natural silica as starting material via a magnesio-mechanochemical reduction process induced by ball-milling. The as-prepared SiOx is intrinsically porous and comprised of mixed nano clusters of SiO2 and Si. Upon lithiation, SiO2 nano domains convert into lithium silicates and Li2O, which help to absorb Si volume expansion and participate in the formation of a stable solid electrolyte interface. Such synergistic effect leads to exceptional cycling stability up to 2000 cycles with 71.3% capacity retention under 4 A g−1. After blending with graphite, a high areal capacity of 2.64 mAh cm−2 demonstrates stable cycling of 89.7% retention over 200 cycles with an high initial Coulombic efficiency of 82.3%, implying the feasibility for practical applications. Structural and compositional characterizations reveal the involved chemistry and evolution mechanism of the formed solid electrolyte interface upon cycling, providing guidelines of designing future silicon-based materials for future Li-ion batteries.
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