Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrol

Abstract

Aqueous lithium-ion batteries may solve the safety problem associated with lithium-ion batteries that use highly toxic and flammable organic solvents, and the poor cycling life associated with commercialized aqueous rechargeable batteries such as lead-acid and nickel-metal hydride systems. But all reported aqueous lithium-ion battery systems have shown poor stability: the capacity retention is typically less than 50% after 100 cycles. Here, the stability of electrode materials in an aqueous electrolyte was extensively analysed. The negative electrodes of aqueous lithium-ion batteries in a discharged state can react with water and oxygen, resulting in capacity fading upon cycling. By eliminating oxygen, adjusting the pH values of the electrolyte and using carbon-coated electrode materials, LiTi2(PO4)3/Li2SO4/LiFePO4 aqueous lithium-ion batteries exhibited excellent stability with capacity retention over 90% after 1,000 cycles when being fully charged/discharged in 10 minutes and 85% after 50 cycles even at a very low current rate of 8 hours for a full charge/discharge offering an energy storage system with high safety, low cost, long cycling life and appropriate energy density. Aqueous lithium-ion batteries have great potential as stationary power sources, but they have had problems with poor stability. A significant improvement in their cycling stability has been achieved by eliminating oxygen, adjusting the electrolyte pH values, and using a carbon-coated electrode material.

Cite this article

Luo, JY., Cui, WJ., He, P. et al. Raising the cycling stability of aqueous lithium-ion batteries by eliminating oxygen in the electrolyte. Nature Chem 2, 760–765 (2010). https://doi.org/10.1038/nchem.763

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