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Published online: 1 September 2010 | doi:10.1038/nchina.2010.99

Electrochemistry: Long live the lithium battery

Felix Cheung

Introduction

© (2010) istockphoto.com/Ingenui

Non-aqueous electrolytes of traditional lithium-ion batteries use highly toxic and flammable organic solvents, which can be dangerous if used improperly. Using aqueous electrolytes can avoid this problem, but an aqueous lithium-ion battery typically loses half of its battery capacity after 100 charge–discharge cycles. Yongyao Xia and co-workers at Fudan University in Shanghai¹ have now devised several strategies to prolong the lifetimes of such aqueous batteries.

A battery loses capacity when its electrodes oxidize and internal resistance increases. The researchers analysed the stability of electrode materials in aqueous electrolytes and found that negative electrodes react with water and oxygen during discharge, which causes capacity fading upon charge–discharge cycling. They improved the stability of aqueous lithium-ion batteries by eliminating oxygen, adjusting the pH of the electrolyte and using carbon-coated electrode materials. The capacity retention of their batteries was over 90% after 1,000 cycles.

By implementing these strategies, aqueous lithium-ion batteries may offer an energy-storage system with high safety, low cost and long lifetime.

The authors of this work are from:
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai, China.

Reference

1. Luo, J. Y., Cui, W. J., He, P. & Xia, Y. Y. Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrolyte. Nature Chem. doi:10.1038/nchem.763 (2010). | Article | OpenURL