In-situ visualization of the space-charge-layer effect on interfacial lithium-ion transport in all-solid-state batteries.

Wang, Longlong; Xie, Ruicong; Chen, Bingbing; Yu, Xinrun; Ma, Jun; Li, Chao; Hu, Zhiwei; Sun, Xingwei et al. · Nat Commun · 2020

basic_science · Level V

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Abstract

The space charge layer (SCL) is generally considered one of the origins of the sluggish interfacial lithium-ion transport in all-solid-state lithium-ion batteries (ASSLIBs). However, in-situ visualization of the SCL effect on the interfacial lithium-ion transport in sulfide-based ASSLIBs is still a great challenge. Here, we directly observe the electrode/electrolyte interface lithium-ion accumulation resulting from the SCL by investigating the net-charge-density distribution across the high-voltage LiCoO<sub>2</sub>/argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl interface using the in-situ differential phase contrast scanning transmission electron microscopy (DPC-STEM) technique. Moreover, we further demonstrate a built-in electric field and chemical potential coupling strategy to reduce the SCL formation and boost lithium-ion transport across the electrode/electrolyte interface by the in-situ DPC-STEM technique and finite element method simulations. Our findings will strikingly advance the fundamental scientific understanding of the SCL mechanism in ASSLIBs and shed light on rational electrode/electrolyte interface design for high-rate performance ASSLIBs.