Ortho-di-sodium salts of tetrahydroxyquinone as a novel electrode for lithium-ion and potassium-ion batteries

Organic electrode materials with superiorities of low price, structural diversity, abundant resources and renewability have been regarded as the promising candidates for rechargeable batteries. However, the poor electronic conductivity and strong solubility in aprotic electrolytes limit the applications for energy storage systems. Here, the ortho-di-sodium salts of tetrahydroxyquinone (o-Na2C6H2O6) was successfully designed via a facile salinization process. Benefitted from the salt formation, the o-Na2C6H2O6 electrode exhibits a potential electrochemical performance, when applied to lithium-ion batteries and potassiumion batteries for the first time. For Li-ion batteries, it delivers a good reversible capacity of 141mA h g(-1) over 100 cycles at 25 mA g(-1), outstanding rate performance of 55.0mA h g(-1) at 5 A g(-1) rate and the long cyclability with a capacity decay of 0.0075% per cycle at 5 A g(-1) exceeding 2000 cycles. On the other hand, the o-Na2C6H2O6 also exhibits a high reversible capacity of 168.1mA h g(-1) under the current density of 25 mA g(-1), good rate performance (26.7 mA h g(-1) at 5 A g(-1) rate) in the K-ion cells. This finding might offer an effective insight to develop other organic salt materials for lithium-ion and potassium-ion batteries. (c) 2018 Elsevier Ltd. All rights reserved.