7,7,8,8-tetracyanoquinodimethane (TCNQ) is a low-cost redox active organic compound which has high theoretic specific capacity. But when it is used as cathode material in batteries, it always suffers from fast performance decaying because of material dissolution. In this work, Al³⁺ salt is added in a Na₂ SO₄ /ZnSO₄ aqueous electrolyte to stabilize the crystalline structure of TCNQ and depress its solubility. Surprisingly, we found the insertion/extraction of high valent cations (Al³⁺ and Zn²⁺) in TCNQ is highly reversible, which leads to synergistic improvement of both specific capacity and cycle life. The obtained cathode exhibits a reversible capacity of 245.8 mAh g^-1 at 0.5 A g^-1 and a cycle-life of 1000 rounds at 3 A g^-1 . Our work demonstrates that molecular organic electrode materials are very different from conventional inorganic cathode materials in terms of high valent cation intercalation reversibility. Adding high valent cation salts is a simple and effective way to enhance the electrochemical performance of molecular organic electrode materials, and consequently build low cost, high performance aqueous rechargeable batteries.

7,7,8,8-四氰基醌二甲烷（TCNQ）是一种低成本的氧化还原活性有机化合物，具有很高的理论比容量。但作为电池正极材料使用时，由于材料溶解，性能衰减快。在这项工作中，将 Al ³⁺盐添加到 Na ₂ SO ₄ /ZnSO ₄水性电解质中以稳定 TCNQ 的晶体结构并降低其溶解度。令人惊讶的是，我们发现高价阳离子（Al ³⁺和 Zn ²⁺）在 TCNQ 中的插入/提取是高度可逆的，这导致比容量和循环寿命的协同提高。所得正极的可逆容量为 245.8 mAh g ^-1在 0.5 A g ^-1和在 3 A g ^{-1 下}循环寿命为 1000 轮。我们的工作表明，分子有机电极材料在高价阳离子嵌入可逆性方面与常规无机正极材料有很大不同。添加高价阳离子盐是提高分子有机电极材料电化学性能的一种简单有效的方法，从而构建低成本、高性能的水性可充电电池。