Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai 200433, China.
Nat Chem. 2010 Sep;2(9):760-5. doi: 10.1038/nchem.763. Epub 2010 Aug 8.
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, LiTi(2)(PO(4))(3)/Li(2)SO(4)/LiFePO(4) 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.
水系锂离子电池可能解决与使用高毒性和易燃有机溶剂的锂离子电池相关的安全问题，以及与商业化水系可充电电池（如铅酸和镍金属氢化物系统）相关的循环寿命差的问题。但是，所有报道的水系锂离子电池系统都表现出较差的稳定性：在 100 次循环后，容量保持率通常小于 50%。在这里，广泛分析了水系电解质中电极材料的稳定性。在放电状态下水系锂离子电池的负极可以与水和氧气反应，导致循环时容量衰减。通过消除氧气、调整电解质的 pH 值和使用碳包覆的电极材料，LiTi(2)(PO(4))(3)/Li(2)SO(4)/LiFePO(4)水系锂离子电池在 10 分钟内完全充电/放电 1,000 次后表现出优异的稳定性，容量保持率超过 90%，即使在非常低的电流速率 8 小时下进行完全充电/放电 50 次后，容量保持率仍为 85%，提供了一种具有高安全性、低成本、长循环寿命和适当能量密度的储能系统。
