Boosting Superior Lithium Storage Performance of Alloy‐Based Anode Materials via Ultraconformal Sb Coating–Derived Favorable Solid‐Electrolyte Interphase. Issue 4 (13th December 2019)

• Record Type: Journal Article
• Authors: Xiong, Bing‐Qing; Zhou, Xinwei; Xu, Gui‐Liang; Liu, Yuzi; Zhu, Likun; Hu, Youcheng; Shen, Shou‐Yu; Hong, Yu‐Hao; Wan, Si‐Cheng; Liu, Xiao‐Chen; Liu, Xiang; Chen, Shengli; Huang, Ling; Sun, Shi‐Gang; Amine, Khalil; Ke, Fu‐Sheng
• Is Part Of: Advanced energy materials. Volume 10:Issue 4(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-12-13
• Subjects: anode materials -- antimony -- batteries -- catalytic decomposition -- solid‐electrolyte interphase; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201903186
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Alloy materials such as Si and Ge are attractive as high‐capacity anodes for rechargeable batteries, but such anodes undergo severe capacity degradation during discharge–charge processes. Compared to the over‐emphasized efforts on the electrode structure design to mitigate the volume changes, understanding and engineering of the solid‐electrolyte interphase (SEI) are significantly lacking. This work demonstrates that modifying the surface of alloy‐based anode materials by building an ultraconformal layer of Sb can significantly enhance their structural and interfacial stability during cycling. Combined experimental and theoretical studies consistently reveal that the ultraconformal Sb layer is dynamically converted to Li3 Sb during cycling, which can selectively adsorb and catalytically decompose electrolyte additives to form a robust, thin, and dense LiF‐dominated SEI, and simultaneously restrain the decomposition of electrolyte solvents. Hence, the Sb‐coated porous Ge electrode delivers much higher initial Coulombic efficiency of 85% and higher reversible capacity of 1046 mAh g −1 after 200 cycles at 500 mA g −1, compared to only 72% and 170 mAh g −1 for bare porous Ge. The present finding has indicated that tailoring surface structures of electrode materials is an appealing approach to construct a robust SEI and achieve long‐term cycling stability for alloy‐based anode materials. Abstract : A simple approach to favorable solid‐electrolyte interphase (SEI) design for alloy‐based anodes is proposed by surface coating of an ultraconformal Sb layer. This strategy can guide and regulate the catalytic decomposition of electrolyte components, leading to the formation of robust, thin, and dense LiF‐dominated SEI. Hence, both cycle stability and initial Coulombic efficiency of alloy‐based anodes are remarkably improved.