Researchers in China have developed a nitroaromatic cathode that performs a six-electron reaction per nitro group, significantly improving the specific capacity and energy density compared with organic electrodes based on single-electron reactions.
Based on such a reaction mechanism, the organic cathode of 1,5-dinitronaphthalene demonstrates an ultrahigh specific capacity of 1,338 mAh⋅g−1 and energy density of 3,273 Wh⋅kg−1, which surpass all existing organic cathodes. A paper on the work is published in Proceedings of the National Academy of Sciences (PNAS).
Organic and polymer materials are of great interest as electrode materials for rechargeable lithium batteries because of the low cost, raw materials abundance, environmental benignity, and high sustainability.
However, the researchers note, traditional organic electrodes typically experience a single-electron reaction per active group, leading to limited specific capacities and energy densities.
In the new nitroaromatic cathode, six-electron transfer occurs on each nitro group, resulting in an ultrahigh specific capacity and energy density, higher than all existing organic electrode materials and even most inorganic electrode materials.
The reaction path was verified as a conversion from nitro to amino groups. Our findings open up a pathway, in terms of battery chemistry, for ultrahigh-energy-density Li-organic batteries.
Zifeng Chen, Hai Su, Pengfei Sun, Panxing Bai, Jixing Yang, Mengjie Li, Yunfeng Deng, Yang Liu, Yanhou Geng, Yunhua Xu (2022) “A nitroaromatic cathode with an ultrahigh energy density based on six-electron reaction per nitro group for lithium batteries” Proceedings of the National Academy of Sciences 119 (6) e2116775119; doi: 10.1073/pnas.2116775119