Catalysis and Interfacial Chemistry in Lithium Batteries: A Surface Science Approach

Abstract

Control of the interfacial chemistry of the electrodes in lithium batteries is vitally important to their safe and effective application. Water and virtually every organic solvent is thermodynamically unstable in the presence of metallic lithium. The electrode potential of a graphite electrode in a lithium-ion battery at the top of charge is at an equivalent chemical potential. In principle, the entire lithium or charged graphite electrode can be completely consumed by reaction with the solvent if the interfacial chemistry is not adventitious, i.e. does not form a reaction self-limiting passive film. A greater understanding of the reactions of the electrolyte and the nature of passivity will be essential to utilize metallic lithium or hosts like silicon that store equivalent amounts of lithium. A surface science approach, like that presented here but now out of fashion, may provide additional insight to approaches currently being used.

Electrochemical Reactivity and Passivation of Silicon Thin-Film Electrodes in Organic Carbonate Electrolytes

“…On the other hand, the mechanism and kinetics of electrochemical reduction of the electrolyte can be altered by the electrode surface structure and composition. 32,33 A fundamental understanding of electrochemical and chemical processes occurring at the Si/electrolyte interface is essential for the development of the next generation of high-energy anode materials.…”

In Situ Potentiodynamic Analysis of the Electrolyte/Silicon Electrodes Interface Reactions - A Sum Frequency Generation Vibrational Spectroscopy Study

“…Previous studies from this laboratory have indicated that the nature of the electrolyte consuming reactions in lithium batteries is electrode material dependent. , …”

Direct monitoring of trace water in Li-ion batteries using operando fluorescence spectroscopy

“…Firstly, water can react with active lithium foils and the common electrolyte, LiPF 6 , thus resulting in capacity fading. 7 , 8 Secondly, water can destroy the protective solid electrolyte interface (SEI) layer, which works as a kind of passivation layer to protect the electrodes’ active components, and prevents electrolyte degradation by resisting electron transport and allowing lithium ions to pass through. 9 , 10 Moreover, water can be reduced on the anode to yield hydrogen gas, increasing the internal pressure of the battery, which will further bring about potential safety hazards.…”