Visualization of Functional Components in a Lithium Silicon Titanium Phosphate-Natural Graphite Composite Anode

Abstract

Here, a multimodal scanning probe microscopy study of a composite anode with a dispersed lithium silicon titanium phosphate (LSTP) lithium ion conductor for all-solid-state batteries is presented. Using electrochemical strain microscopy (ESM) and lateral force microscopy (LFM), electromechanical response and friction force dependence as a function of the measurement parameters such as the tip loading force and AC drive voltage are analyzed. The sensitivities of friction force and ESM amplitude are found to be valid markers to identify each component in the composite anode. Furthermore, the distribution of active ionic sites of lithium ions is visualized in the comingled region of LSTP and binder materials based on Pearson's correlation analysis between nanoscale ESM and LFM results. With the suggested technique, various components of composite electrodes can be directly visualized and distinguished in ambient conditions, with their properties being measured simultaneously. These methods will provide insights into the optimal conditions of composite electrodes and allow for developing next-generation all-solid-state batteries.