title: Highly stable Na2/3 (Mn0.54 Ni0.13 Co0.13 )O2 cathode modified by atomic layer deposition for sodium-ion batteries.
abstract: For the first time, atomic layer deposition (ALD) of Al2 O3 was adopted to enhance the cyclic stability of layered P2-type Na2/3 (Mn0.54 Ni0.13 Co0.13 )O2 (MNC) cathodes for use in sodium-ion batteries (SIBs). Discharge capacities of approximately 120, 123, 113, and 105 mA h g(-1) were obtained for the pristine electrode and electrodes coated with 2, 5, and 10 ALD cycles, respectively. All electrodes were cycled at the 1C discharge current rate for voltages between 2 and 4.5 V in 1 M NaClO4 electrolyte. Among the electrodes tested, the Al2 O3 coating from 2 ALD cycles (MNC-2) exhibited the best electrochemical stability and rate capability, whereas the electrode coated by 10 ALD cycles (MNC-10) displayed the highest columbic efficiency (CE), which exceeded 97 % after 100 cycles. The enhanced electrochemical stability observed for ALD-coated electrodes could be a result of the protection effects and high band-gap energy (Eg =9.00 eV) of the Al2 O3 coating layer. Additionally, the metal-oxide coating provides structural stability against mechanical stresses occurring during the cycling process. The capacity, cyclic stability, and rate performance achieved for the MNC electrode coated with 2 ALD cycles of Al2 O3 reveal the best results for SIBs. This study provides a promising route toward increasing the stability and CE of electrode materials for SIB application.
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada).
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Kaliyappan
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada).
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada).
authors.forename: Andrew
authors.initials: A
authors.lastname: Lushington
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada).
authors.forename: Ruying
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, N6A 5B9 (Canada). xsun@eng.uwo.ca.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Sun
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D008345:Manganese / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry
chemical_list: D010087:Oxides; D003035:Cobalt; D008345:Manganese; D009532:Nickel; D012964:Sodium; D000537:Aluminum Oxide
keywords: aluminum; atomic layer deposition; batteries; electrochemistry; sodium