Self‐Supporting, Flexible, Additive‐Free, and Scalable Hard Carbon Paper Self‐Interwoven by 1D Microbelts: Superb Room/Low‐Temperature Sodium Storage and Working Mechanism

• Published in: Advanced materials (Weinheim) Vol. 31; no. 40; pp. e1903125 - n/a
• Main Authors: Hou, Bao‐Hua, Wang, Ying‐Ying, Ning, Qiu‐Li, Li, Wen‐Hao, Xi, Xiao‐Tong, Yang, Xu, Liang, Hao‐Jie, Feng, Xi, Wu, Xing‐Long
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.10.2019
• Subjects: anode materials; Anodes; Carbon; carbon paper; Electrode materials; Electrolytes; flexible; Low temperature; Materials science; Reaction kinetics; Rechargeable batteries; sodium‐ion batteries; tissue; anode materials; tissue; sodium-ion batteries; flexible; carbon paper
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.201903125

Hard carbon is regarded as a promising anode material for sodium‐ion batteries (SIBs). However, it usually suffers from the issues of low initial Coulombic efficiency (ICE) and poor rate performance, severely hindering its practical application. Herein, a flexible, self‐supporting, and scalable hard carbon paper (HCP) derived from scalable and renewable tissue is rationally designed and prepared as practical additive‐free anode for room/low‐temperature SIBs with high ICE. In ether electrolyte, such HCP achieves an ICE of up to 91.2% with superior high‐rate capability, ultralong cycle life (e.g., 93% capacity retention over 1000 cycles at 200 mA g−1) and outstanding low‐temperature performance. Working mechanism analyses reveal that the plateau region is the rate‐determining step for HCP with a lower electrochemical reaction kinetics, which can be significantly improved in ether electrolyte. A self‐supporting, flexible, additive‐free and scalable hard carbon paper (HCP) derived from tissue is rationally developed, and it achieves outstanding Na‐storage properties in terms of high initial Coulombic efficiency (91.2%), superior high‐rate capability, ultralong cyclic stability, as well as outstanding low‐T performance in ether electrolyte. More significantly, the Na‐storage and capacity attenuation mechanism of the HCP anode is revealed.