Achieving Sustainable and Stable Potassium‐Ion Batteries by Leaf‐Bioinspired Nanofluidic Flow

• Published in: Advanced materials (Weinheim) Vol. 34; no. 39; pp. e2204370 - n/a
• Main Authors: Zhang, Xixue, Wu, Feng, Lv, Xiaowei, Xu, Liqianyun, Huang, Ruling, Chen, Renjie, Li, Li
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-09-2022
• Subjects: Batteries; bioinspired materials; Biomimetics; Cobalt sulfide; Decay rate; Dissolution; Electrodes; Energy conversion; Fluidics; Materials science; nanofluidics; Nanofluids; Porous media; potassium‐ion batteries; Rechargeable batteries; spent batteries’ recycling; System effectiveness
• DOI: 10.1002/adma.202204370
• EISSN: 1521-4095
• ISSN: 0935-9648

In nature, living systems have evolved integrated structures, matching optimized nanofluidics to adapt to external conditions. In rechargeable batteries, high‐capacity electrodes are often plagued by the crucial and universal bottleneck of dissolution and shuttle of active substance into electrolyte, posing obstacles of inevitable capacity degradation. Introducing the concept of intelligent nanofluidics to electrodes, a leaf‐bioinspired electrode configuration with hierarchical architecture to tackle this problem is proposed. This integrated structure with fine‐tuned surface pores and unobstructed interior porous media, can spatially control the anisotropic nanofluidic flux, in an efficient and self‐protectable way: tailoring the outflow across the electrode's surface and free transport in interior, to ensure speedy and stable energy conversion. As proofs of concept, applications of sustainable electrodes rejuvenated from fallen leaf and spent commercial batteries, are designed with leaf‐bioinspired architecture. Both KCoS2 and KS battery systems show advanced steady cycling with effectively mitigated shuttle issues in this smart architecture (0.15% and 0.21% capacity decay per cycle), even at high areal mass loading, when compared with open porous structure (0.60% and 0.39%). This work may pave a new way from a biomimetic view to integrated electrode engineering with regulated surface shielding to conquer the universal dissolution–shuttle problems facing high‐capacity materials.
A leaf‐bioinspired electrode configuration with nanofluidic flow is proposed. When applied in KCoS2 and KS battery systems, the designed sustainable electrodes show advanced steady cycling stability and rapid energy conversion. This biomimetic integrated electrode engineering can enable anisotropic electrolyte flux to achieve regulated surface shielding, which may be a universal way to tackle the shuttle problems facing high‐capacity electrodes.