Highly Flexible K‐Intercalated MnO2/Carbon Membrane for High‐Performance Aqueous Zinc‐Ion Battery Cathode

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-01, Vol.19 (1), p.e2205544-n/a
• Main Authors: Yang, Jie, Yao, Ge, Li, Zhiqiang, Zhang, Yuhang, Wei, Lingzhi, Niu, Helin, Chen, Qianwang, Zheng, Fangcai
• Format: Article
• Language: English
• Subjects: Carbon; carbon membranes; Cathodes; Commercialization; Electrical resistivity; Electrochemical analysis; Electrode materials; flexible electrodes; Intercalation; Interlayers; K ion intercalation; Manganese dioxide; Membranes; MnO 2; Nanotechnology; Structural damage; Structural stability; Zinc; zinc‐ion batteries
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202205544

The layered MnO2 is intensively investigated as one of the most promising cathode materials for aqueous zinc‐ion batteries (AZIBs), but its commercialization is severely impeded by the challenging issues of the inferior intrinsic electronic conductivity and undesirable structural stability during the charge–discharge cycles. Herein, the lab‐prepared flexible carbon membrane with highly electrical conductivity is first used as the matrix to generate ultrathin δ‐MnO2 with an enlarged interlayer spacing induced by the K+‐intercalation to potentially alleviate the structural damage caused by H+/Zn2+ co‐intercalation, resulting in a high reversible capacity of 190 mAh g−1 at 3 A g−1 over 1000 cycles. The in situ/ex‐situ characterizations and electrochemical analysis confirm that the enlarged interlayer spacing can provide free space for the reversible deintercalation/intercalation of H+/Zn2+ in the structure of δ‐MnO2, and H+/Zn2+ co‐intercalation mechanism contributes to the enhanced charge storage in the layered K+‐intercalated δ‐MnO2. This work provides a plausible way to construct a flexible carbon membrane‐based cathode for high‐performance AZIBs. Herein, the lab‐prepared flexible carbon membrane is taken as the matrix to generate ultrathin K+‐intercalated δ‐MnO2 (denoted as KMO/CNFs). The K+‐intercalated δ‐MnO2 provides an enhanced interlayer spacing to alleviate the structural damage caused by H+/Zn2+ intercalation, and the flexible carbon membrane promotes the electron conduction, resulting in enhanced reaction kinetics and cycling stability in aqueous electrolyte.