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Diatomite‐Derived Hierarchical Porous Crystalline‐AmorphousNetwork for High‐Performance and Sustainable Si Anodes
Author(s) -
Zhang Ying,
Zhang Rui,
Chen Shucheng,
Gao Hongpeng,
Li Mingqian,
Song Xiaolan,
Xin Huolin L.,
Chen Zheng
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202005956
Subject(s) - materials science , anode , amorphous solid , porosity , chemical engineering , cathode , composite number , electrochemistry , silicon , lithium (medication) , coating , nanotechnology , composite material , electrode , metallurgy , medicine , organic chemistry , chemistry , engineering , endocrinology
Silicon has attracted considerable interest as a high‐capacity anode material for next‐generation lithium‐ion batteries. However, Si‐based anodes suffer extreme volume change ( ≈ 380%) upon lithiation and delithiation, which results in rapid capacity fading due to mechanical and electrochemical failure during cycling. Herein, a sustainable and scalable method to synthesize hierarchically porous micron‐sized Si particles from the low‐cost diatomite precursor is reported, which serves as both the precursor and the template. Through a one‐step magnesiothermic reduction, the SiO 2 constituent in diatomite is reduced to form a Si/SiO 2 composite network with 10–30 nm crystalline Si domains embedded within an amorphous SiO 2 matrix. Controlling the reduction time leads to an optimal ratio between the crystalline Si and the amorphous SiO 2 constituent, which endows the composite structure with high capacity and excellent cycling stability. For example, 90% capacity can be retained after 500 cycles at 0.2C for sample reduced by 6 h without any coating or prelithiation. The full cell with such Si/SiO 2 as the anode and LiNi 0.8 Co 0.1 Mn 0.1 O 2 as the cathode shows ≈ 80% capacity retention after 200 cycles. This work creates a unique path towards sustainable and scalable production of high‐performance micron‐sized Si anodes, offering new opportunities for potential industrial applications.