Self‐Thermal Management in Filtered Selenium‐Terminated MXene Films for Flexible Safe Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 20; no. 36; pp. e2309580 - n/a
• Main Authors: Pang, Xin, Lee, Hyunjin, Rong, Jingzhi, Zhu, Qiaoyu, Xu, Shumao
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2024
• Subjects: Electrical resistivity; Electrodes; functional groups terminated MXene; High temperature; high‐rate and flexible battery; Infrared radiation; infrared‐transparent; internal thermal management; Lewis acid; Lithium-ion batteries; MXenes; Permittivity; Radiation; safe; Selenium; Storage capacity; Structural stability; Thermal management; Thermal radiation; Thermal runaway; Vacuum filtration; internal thermal management; safe; functional groups terminated MXene; high‐rate and flexible battery; infrared‐transparent
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202309580

Li‐ion batteries with superior interior thermal management are crucial to prevent thermal runaway and ensure safe, long‐lasting operation at high temperatures or during rapid discharging and charging. Typically, such thermal management is achieved by focusing on the separator and electrolyte. Here, the study introduces a Se‐terminated MXene free‐standing electrode with exceptional electrical conductivity and low infrared emissivity, synergistically combining high‐rate capacity with reduced heat radiation for safe, large, and fast Li+ storage. This is achieved through a one‐step organic Lewis acid‐assisted gas‐phase reaction and vacuum filtration. The Se‐terminated Nb2Se2C outperformed conventional disordered O/OH/F‐terminated materials, enhancing Li+‐storage capacity by ≈1.5 times in the fifth cycle (221 mAh·g−1 at 1 A·g−1) and improving mid‐infrared adsorption with low thermal radiation. These benefits result from its superior electrical conductivity, excellent structural stability, and high permittivity in the infrared region. Calculations further reveal that increased permittivity and conductivity along the z‐direction can reduce heat radiation from electrodes. This work highlights the potential of surface groups‐terminated layered material‐based free‐standing flexible electrodes with self‐thermal management ability for safe, fast energy storage. A filtered Se‐terminated MXene flexible electrode not only enhances the Li storage capacity but also possesses a unique ability of low thermal emissivity, significantly reducing the risk of overheating. The developed flexible battery enables large, fast, and safe energy storage, promising for safe and fast‐charging applications.