Raising the Redox Potential in a Quinone-Based Positive Organic Cathode via Space Charge Modulation

Recently, π-d conjugated coordination polymers (CCPs) have been emerging in the field of energy storage due to their high conductivity, low solubility, and structural diversity. In this paper, we report a nickel tetrahydroxy-p-benzoquinone complex (Ni-PTHBQ) with a detailed analysis of its structure and components for the first time. The application of Ni-PTHBQ to lithium storage was found to have a high lithium storage potential of 3.12 V. The charging–discharging mechanism of the 2.5 e– transfer of Ni-PTHBQ was demonstrated by in situ Raman spectroscopy and other tests. In addition, the reason for the capacity degradation of Ni-PTHBQ was revealed by in situ XRD. This work clarifies the structure and lithium storage mechanism of Ni-PTHBQ, which provides a strong guidance for the synthesis and preparation of CCPs materials as well as their application in energy storage.