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Operando surface science methodology reveals surface effect in charge storage electrodes.

ABSTRACT: Surface and interface play critical roles in energy storage devices, calling for operando characterization techniques to probe the electrified surfaces/interfaces. In this work, surface science methodology, including electron spectroscopy and scanning probe microscopy, has been successfully applied to visualize electrochemical processes at operating electrode surfaces in an Al/graphite model battery. Intercalation of anions together with cations is directly observed in the surface region of a graphite electrode with tens of nanometers thickness, the concentration of which is one order higher than that in bulk. An intercalation pseudocapacitance mechanism and a double specific capacity in the electrode surface region are expected based on the super-dense intercalants and anion/cation co-intercalation, which are in sharp contrast to the battery-like mechanism in the electrode bulk. The distinct electrochemical mechanism at the electrode surface is verified by performance tests of real battery devices, showing that a surface-dominant, nanometer-thick graphite cathode outperforms a bulk-dominant, micrometer-thick graphite cathode. Our findings highlight the important surface effect of working electrodes in charge storage systems.

SUBMITTER: Wang C

PROVIDER: S-EPMC8288451 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Operando surface science methodology reveals surface effect in charge storage electrodes.

Wang Chao C Ning Yanxiao Y Huang Haibo H Li Shiwen S Xiao Chuanhai C Chen Qi Q Peng Li L Guo Shuainan S Li Yifan Y Liu Conghui C Wu Zhong-Shuai ZS Li Xianfeng X Chen Liwei L Gao Chao C Wu Chuan C Fu Qiang Q

National science review 20201208 3

Surface and interface play critical roles in energy storage devices, calling for operando characterization techniques to probe the electrified surfaces/interfaces. In this work, surface science methodology, including electron spectroscopy and scanning probe microscopy, has been successfully applied to visualize electrochemical processes at operating electrode surfaces in an Al/graphite model battery. Intercalation of anions together with cations is directly observed in the surface region of a gr ...[more]

PMID: 34691600

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Operando surface science methodology reveals surface effect in charge storage electrodes.

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Operando surface science methodology reveals surface effect in charge storage electrodes.

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