Zhang Qiu, Liu Xiaomeng, Lu Yong, Ni Youxuan, Xie Weiwei, Yan Zhenhua, Li Fujun, Chen Jun
Frontiers Science Center for New Organic Matter, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), State Key Laboratory of Advanced Chemical Power Sources, College of Chemistry, Nankai University, Tianjin 300071, China.
J Am Chem Soc. 2024 Feb 28;146(8):5597-5604. doi: 10.1021/jacs.3c13963. Epub 2024 Feb 17.
Rechargeable aqueous batteries are potential systems for large-scale energy storage due to their high safety and low cost. However, developing aqueous batteries with high sustainability, affordability, and reversibility is urgent and challenging. Here we report an amphoteric aluminum hydroxyacetate (AlAc(OH)) electrolyte with the ability of bipolar ionization of H and OH, which facilitates the redox reactions at both the anthraquinone (AQ) anode and nickel hydroxide (Ni(OH)) cathode. The bipolar ionization ability of the AlAc(OH)(HO) solvation structure results from the strong polarization ability of Al and OH. The H/OH dissociation ability with a dissociation constant of 5.0/3.0 is stronger than that of water (14.0), which boosts the simultaneous stable redox reactions of electrodes. Specifically, H uptake prevents the AQ anode from the formation of an ionic bond, suppressing the electrode dissolution, whereas OH provides the local alkaline environment for the stable conversion reaction of the Ni(OH) cathode. The AQ anode in the designed AQ||Ni(OH) battery delivers a discharge capacity of 243.9 mAh g and a capacity retention of 78.2% after 300 cycles with high reversibility. Moreover, a pouch cell with a discharge capacity of 0.90 Ah was assembled, exhibiting an energy density of 44.7 Wh kg based on the total mass of the battery. This work significantly widens the types of aqueous batteries and represents a design philosophy of bipolar electrolytes and distinct electrochemical reactions with H and OH.
可充电水系电池因其高安全性和低成本而成为大规模储能的潜在体系。然而，开发具有高可持续性、可承受性和可逆性的水系电池既紧迫又具有挑战性。在此，我们报道了一种两性羟基乙酸铝（AlAc(OH)）电解质，它具有H和OH的双极电离能力，这有助于蒽醌（AQ）阳极和氢氧化镍（Ni(OH)）阴极的氧化还原反应。AlAc(OH)(HO)溶剂化结构的双极电离能力源于Al和OH的强极化能力。其H/OH解离能力的解离常数为5.0/3.0，比水的解离常数（14.0）更强，这促进了电极的同时稳定氧化还原反应。具体而言，H的摄取可防止AQ阳极形成离子键，抑制电极溶解，而OH为Ni(OH)阴极的稳定转化反应提供局部碱性环境。在设计的AQ||Ni(OH)电池中，AQ阳极的放电容量为243.9 mAh g，300次循环后的容量保持率为78.2%，具有高可逆性。此外，组装了一个放电容量为0.90 Ah的软包电池，基于电池的总质量，其能量密度为44.7 Wh kg。这项工作显著拓宽了水系电池的类型，代表了一种双极电解质以及与H和OH的独特电化学反应的设计理念。
