Encapsulating MnO nanoparticles within foam-like carbon nanosheet matrix for fast and durable lithium storage. (August 2018)

• Record Type: Journal Article
• Authors: Xiao, Yu-Chen; Xu, Cheng-Yan; Wang, Pan-Pan; Fang, Hai-Tao; Sun, Xue-Yin; Ma, Fei-Xiang; Pei, Yi; Zhen, Liang
• Is Part Of: Nano energy. Volume 50(2018)
• Page Start: 675
• Page End: 684
• Publication Date: 2018-08
• Subjects: Lithium ion batteries -- Anode materials -- MnO -- Carbon framework -- Internal voids; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.06.018
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Long-life MnO-based anodes with high power density for lithium ion batteries (LIBs) is still a great challenge due to the inferior electrical conductivity and drastic volume change of MnO during the lithiation/delithiation process. Herein, to achieve high rate capacity and long cycle life simultaneously, MnO nanoparticles were encapsulated within a foam-like carbon nanosheet matrix through a confined phase transition process. By annealing polydopamine (PDA) coated porous ZnMnO3 nanosheets in a reducing atmosphere, MnO nanoparticles and surrounding in-situ formed pores could be encapsulated in the PDA-derived carbon nanosheets synchronously, forming MnO@C nanosheets with ball-in-pore structure (MnO@C-BP). The internal voids originating from Zn evaporation can not only accommodate the huge volume expansion of MnO nanoparticles, but also significantly enlarge the specific surface area, leading to an enhanced pseudocapacitive Li-storage behavior. Moreover, the as-prepared sheet-shaped MnO@C-BP with thickness of about 30 nm can provide a short path for fast Li-ion diffusion, while the continuous carbon framework promotes the charge transfer between the encapsulated MnO nanoparticles. Because of these merits, MnO@C-BP electrode exhibits superior rate performance (514 mAh g −1 at 10 A g −1, 383 mAh g −1 at 15 A g −1 ), outstanding cycling performance (1212 mAh g −1 after 1000 cycles at 2 A g −1, capacity retention of 127%), as well as a high reversible capacity of 1178 mAh g −1 at 0.1 A g −1 . Graphical abstract: Foam-like carbon nanosheets embedded with MnO nanoparticles were designed and constructed through a confined phase transition process, which possesses abundant internal voids, multi-point core-shell contact, and 3D conductive framework, and exhibit superior rate capacity (383 mAh g −1 at 15 A g −1 ), as well as outstanding cycling performance (1212 mAh g −1 after 1000 cycles at 2 A g −1 ). fx1 Highlights: Foam-like carbon nanosheets embedded with MnO nanoparticles were fabricated via a confined phase transition process. They possess abundant internal voids, multi-point core-shell contact, and three-dimensional conductive framework. The abundant internal voids contribute to enhanced pseudocapacitive behavior and accommodate the large volume change of MnO. The unique ball-in-pore structure of the MnO@C nanosheets endows them with superior Li-storage performance.