Multifunctional Films Deposited by Atomic Layer Deposition for Tailored Interfaces of Electrochemical Systems

Abstract

A new strategy for electrochemical interfaces that utilizes multilayer films deposited by atomic layer deposition (ALD) is introduced. Manganese-rich and nickel-rich cathode oxides were coated with a novel bilayer film of metal fluorides. Subsequent exposure to prolonged, high-voltage electrochemical cycling vs graphite electrodes revealed that the bilayer film can greatly enhance the high-voltage stability of cathode oxides. In particular, in manganese-rich cells, capacity fade due to manganese dissolution was substantially reduced and impedance rise was virtually eliminated. Furthermore, in nickel-rich NMC-811 cells, impedance rise was reduced by ∼80%, compared to the NMC-811 baseline, after ∼300 h of high-voltage exposure during cycling. The multilayer film strategy presents an exciting opportunity for tailoring designs and materials for electrochemical interfaces in advanced lithium-ion batteries and beyond.