title: Atomic Layer Deposition of Al2O3-Ga2O3 Alloy Coatings for Li[Ni0.5Mn0.3Co0.2]O2 Cathode to Improve Rate Performance in Li-Ion Battery.
abstract: Metal oxide coatings can improve the electrochemical stability of cathodes and hence, their cycle-life in rechargeable batteries. However, such coatings often impose an additional electrical and ionic transport resistance to cathode surfaces leading to poor charge-discharge capacity at high C-rates. Here, a mixed oxide (Al2O3)1-x(Ga2O3)x alloy coating, prepared via atomic layer deposition (ALD), on Li[Ni0.5Mn0.3Co0.2]O2 (NMC) cathodes is developed that has increased electron conductivity and demonstrated an improved rate performance in comparison to uncoated NMC. A "co-pulsing" ALD technique was used which allows intimate and controlled ternary mixing of deposited film to obtain nanometer-thick mixed oxide coatings. Co-pulsing allows for independent control over film composition and thickness in contrast to separate sequential pulsing of the metal sources. (Al2O3)1-x(Ga2O3)x alloy coatings were demonstrated to improve the cycle life of the battery. Cycle tests show that increasing Al-content in alloy coatings increases capacity retention; whereas a mixture of compositions near (Al2O3)0.5(Ga2O3)0.5 was found to produce the optimal rate performance.
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin Madison , 1415 Engineering Drive, Madison, Wisconsin 53706, United States.
authors.forename: Masihhur R
authors.initials: MR
authors.lastname: Laskar
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin Madison , 1415 Engineering Drive, Madison, Wisconsin 53706, United States.
authors.forename: David H K
authors.initials: DH
authors.lastname: Jackson
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin Madison , 1509 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Yingxin
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin Madison , 1509 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Shenzhen
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Chemistry, University of Wisconsin Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Shuyu
authors.initials: S
authors.lastname: Fang
authors.affiliation: The Dow Chemical Company , 1776 building, Midland, Michigan 48674, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Dreibelbis
authors.affiliation: Department of Chemistry, University of Wisconsin Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Mahesh K
authors.initials: MK
authors.lastname: Mahanthappa
authors.affiliation: Department of Material Science and Engineering, University of Wisconsin Madison , 1509 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Dane
authors.initials: D
authors.lastname: Morgan
authors.affiliation: Department of Chemistry, University of Wisconsin Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hamers
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin Madison , 1415 Engineering Drive, Madison, Wisconsin 53706, United States.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Kuech
keywords: Al2O3; Ga2O3; Li-ion battery; NMC cathode; atomic layer deposition; coatings