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Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature
Published on: December 20, 2016
Boosting Ultra-Wide Temperature Sodium-Bromine Batteries via Chlorine-Bromine Activation
Wenting Feng1, Jianhang Yang2, Xinru Wei3
1School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao, 266580, P.R. China.
Abstract:
The development of high-energy-density batteries operable over a wide temperature range is critical for sustainable energy storage. Sodium-chlorine (Na-Cl2) batteries show promising high theoretical energy densities but face significant safety challenges due to gaseous chlorine, particularly at high temperatures. Replacing Cl2 with liquid Br2 to construct a new Na-Br2 battery mitigates gas risks but introduces issues with sluggish reaction kinetics and high-temperature volatility. To overcome these limitations, we developed a revolutionary Na-Br(+) battery based on the activated Br+ by Cl- anions, pioneering a stabilized redox process via Br-/BrCl2 - conversion. The introduction of Cl- enhances the reversibility kinetics of bromine species and facilitating the activation of Br+ through polyanions BrCl2 -, enabling additional electron transfer pathways. The Na-Br(+) battery achieves impressive low polarization (0.18 V) and exhibits wide-temperature functionality (-60 °C to 60 °C) with a cycle life exceeding 400 cycles. This heterogeneous halogen activation strategy addresses key gas safety limitations and advances the practicality of metal-halogen batteries.
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