Flexible free-standing air electrode with bimodal pore architecture for long-cycling Li-O2 batteries
| Autor: | Kisuk Kang, Kwangjin Park, Soonchul Kwon, Mokwon Kim, Hyunpyo Lee, Hyun-Jin Kim, Seongyong Park, Wonsung Choi, Youngjoon Bae, Hyuk Jae Kwon, Dongmin Im, WoonJoong Baek, Tae-Young Kim |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Nanotechnology 02 engineering and technology General Chemistry Electrolyte Carbon nanotube Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Cathode 0104 chemical sciences law.invention Tetraethylene glycol dimethyl ether chemistry.chemical_compound chemistry Chemical engineering law Electrode General Materials Science 0210 nano-technology Leakage (electronics) |
| Zdroj: | Carbon. 117:454-461 |
| ISSN: | 0008-6223 |
| DOI: | 10.1016/j.carbon.2017.03.015 |
| Popis: | Li-O 2 batteries have been proposed as next-generation energy-storage devices, but this technology is hindered by serious problems including parasitic reactions, degradation, and leakage of the electrolyte. Li-O 2 batteries are also currently designed to have a rigid bulky structure, which cannot satisfy the flexibility demands of modern electronics. Herein, we report the significant enhancement of the electrochemical performance and flexibility of a Li-O 2 battery by introducing a free-standing, binder-free carbon nanotube cathode with a bimodal pore architecture. This electrode structure imparted stability to active sites during the recovery of discharge products to the initial state, providing long-term cyclability of more than 100 cycles in a tetraethylene glycol dimethyl ether electrolyte system. The O 2 transportation and conductivity were also improved, yielding an increased discharge capacity of 5500 mAh g −1 (nearly twice that of a non-porous cathode) and minimizing parasitic reactions. This novel bimodal-pore cathode exhibited an increased tri-phase boundary for the Li-O 2 reactive zone in the interconnected CNT network. The small pore structures (∼50 nm) accommodated Li 2 O 2 , and the large pore structures (∼385 nm) enabled effective oxygen diffusion without clogging the pores. Moreover, Li + and oxygen diffusion were facilitated by the two independent channels provided by the pore structures. |
| Databáze: | OpenAIRE |
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