Black Phosphorus Quantum Dot/Ti3C2 MXene Nanosheet Composites for Efficient Electrochemical Lithium/Sodium‐Ion Storage

• Published in: Advanced energy materials Vol. 8; no. 26
• Main Authors: Meng, Ruijin, Huang, Jimei, Feng, Yutong, Zu, Lianhai, Peng, Chengxin, Zheng, Lirong, Zheng, Lei, Chen, Zhibin, Liu, Guanglei, Chen, Bingjie, Mi, Yongli, Yang, Jinhu
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 14-09-2018
• Subjects: Anodes; Atomic properties; Batteries; black phosphorus quantum dots; Cycles; Density functional theory; dual‐model energy storage; Electrode polarization; Electrodes; Electron transfer; Energy storage; Fine structure; Ion storage; Lithium; Li‐ion batteries; MXenes; Nanosheets; Nanostructure; Na‐ion batteries; Phosphorus; Quantum dots; Rechargeable batteries; Spectrum analysis; Storage batteries; Ti3C2 nanosheets (TNSs)
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201801514

The exploration of new and efficient energy storage mechanisms through nanostructured electrode design is crucial for the development of high‐performance rechargeable batteries. Herein, black phosphorus quantum dots (BPQDs) and Ti3C2 nanosheets (TNSs) are employed as battery and pseudocapacitive components, respectively, to construct BPQD/TNS composite anodes with a novel battery‐capacitive dual‐model energy storage (DMES) mechanism for lithium‐ion and sodium‐ion batteries. Specifically, as a battery‐type component, BPQDs anchored on the TNSs are endowed with improved conductivity and relieved stress upon cycling, enabling a high‐capacity and stable energy storage. Meanwhile, the pseudocapacitive TNS component with further atomic charge polarization induced by POTi interfacial bonds between the two components allows enhanced charge adsorption and efficient interfacial electron transfer, contributing a higher pseudocapacitive value and fast energy storage. The DMES mechanism is evidenced by substantial characterizations of X‐ray photoelectron spectroscopy and X‐ray absorption fine structure spectroscopy, density functional theory calculations, and kinetics analyses. Consequently, the composite electrode exhibits superior battery performance, especially for lithium storage, such as high capacity (910 mAh g−1 at 100 mA g−1), long cycling stability (2400 cycles with a capacity retention over 100%), and high rate capability, representing the best comprehensive battery performance in BP‐based anodes to date.
A novel working mechanism of battery‐capacitive dual‐model energy storage for high‐performance lithium‐ion batteries is proposed, which is enabled in composite anodes combining black phosphorus quantum dots and Ti3C2 nanosheets as battery and pseudocapacitive components, respectively.