High areal capacity, long cycle life Li-O2 cathode based on highly elastic gel granules. (May 2018)

• Record Type: Journal Article
• Authors: Chen, Wanqi; Yin, Wei; Shen, Yue; Huang, Zhaoming; Li, Xianglin; Wang, Fangzhou; Zhang, Wang; Deng, Zhe; Zhang, Zhuoran; Huang, Yunhui
• Is Part Of: Nano energy. Volume 47(2018)
• Page Start: 353
• Page End: 360
• Publication Date: 2018-05
• Subjects: Li-O2 battery -- Areal capacity -- Elastic polymer -- Li2O2 growth -- Gel; 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.2018.03.005
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: We introduce a "gelating-cutting" strategy to improve specific areal capacity and cycle life for Li-O2 cathode. Conventional Li-O2 cathode with liquid electrolyte is gelated with highly elastic crosslinked polymer and cut into 50–200 µm granules. The gaps between the packed gel granules efficiently induce oxygen to the inner part of the cathode, leading to even Li2 O2 growth in thick cathode. Meanwhile, the elasticity of the polymer chain helps to keep good contact between carbon and Li2 O2 nanoparticles, which facilitates the electron transfer and improves the cyclability. Without any catalyst, the granular gel cathode is able to run 170 cycles at a fixed capacity of 1000 mA h gcarbon −1, or maintains a specific capacity higher than 10, 500 mA h gcarbon −1 (12.6 mA h cm −2 ) during 11 cycles of full discharge-charge. Since good contact is the precondition to any electrochemical reaction, our strategy is a general way to enhance the performance of Li-O2 cathodes. Graphical abstract: fx1 Highlights: Porous cathode and catholyte is gelated and cut into granules to facilitate oxygen diffusion. The growth of Li2 O2 is found at the inner part of the cathode with thickness up to 1 mm. The superior elasticity of the polymer in the gel helps to keep good Li2 O2 -carbon contact and improves the cyclability. The areal capacity and cycle life of the cathode improved synergistically without using catalyst.