Pascalammetry with operando microbattery probes: Sensing high stress in solid-state batteries.

Larson, Jonathan M; Gillette, Eleanor; Burson, Kristen; Wang, Yilin; Lee, Sang Bok; Reutt-Robey, Janice E · Sci Adv · 2018

basic_science · Level V

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Abstract

Energy storage science calls for techniques to elucidate ion transport over a range of conditions and scales. We introduce a new technique, pascalammetry, in which stress is applied to a solid-state electrochemical device and induced faradaic current transients are measured and analyzed. Stress-step pascalammetry measurements are performed on operando microbattery probes (Li<sub>2</sub>O/Li/W) and Si cathodes, revealing stress-assisted Li<sup>+</sup> diffusion. We show how non-Cottrellian lithium diffusional kinetics indicates stress, a prelude to battery degradation. An analytical solution to a diffusion/activation equation describes this stress signature, with spatiotemporal characteristics distinct from Cottrell's classic solution for unstressed systems. These findings create an unprecedented opportunity for quantitative detection of stress in solid-state batteries through the current signature. Generally, pascalammetry offers a powerful new approach to study stress-related phenomena in any solid-state electrochemical system.