title: Low-Cost Al2O3 Coating Layer As a Preformed SEI on Natural Graphite Powder To Improve Coulombic Efficiency and High-Rate Cycling Stability of Lithium-Ion Batteries.
abstract: Coulombic efficiency especially in the first cycle, cycling stability, and high-rate performance are crucial factors for commercial Li-ion batteries (LIBs). To improve them, in this work, Al2O3-coated natural graphite powder was obtained through a low-cost and facile sol-gel method. Based on a comparison of various coated amounts, 0.5 mol % Al(NO3)3 (vs mole of graphite) could bring about a smooth Al2O3 coating layer with proper thickness, which could act as a preformed solid electrolyte interface (SEI) to reduce the regeneration of SEI and lithium-ions consumption during subsequent cycling. Furthermore, we examined the advantages of Al2O3 coating by relating energy levels in LIBs using density functional theory calculations. Owing to its proper bandgap and lithium-ion conduction ability, the coating layer performs the same function as a SEI does, preventing an electron from getting to the outer electrode surface and allowing lithium-ion transport. Therefore, as a preformed SEI, the Al2O3 coating layer reduces extra cathode consumption observed in commercial LIBs.
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University , Xi'an 710049, China.|Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University , Xi'an 710049, China.|Institut für Chemie, AG Elektrochemie, Technische Universität Chemnitz , 09111 Chemnitz, Germany.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Feng
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University , Xi'an 710049, China.|Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Youlong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University , Xi'an 710049, China.|Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Du
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University , Xi'an 710049, China.|Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Sun
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University , Xi'an 710049, China.|Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Lilong
authors.initials: L
authors.lastname: Xiong
authors.affiliation: Institut für Physik, Technische Universität Chemnitz , 09111 Chemnitz, Germany.
authors.forename: Raul
authors.initials: R
authors.lastname: Rodriguez
authors.affiliation: Institut für Chemie, AG Elektrochemie, Technische Universität Chemnitz , 09111 Chemnitz, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Holze
keywords: DFT calculations; SEI; alumina coating; anodes; energy levels; lithium-ion batteries