Redox flow batteries (RFBs) provide an attractive solution for large-scale energy buffering and storage. This report describes the development of nonaqueous RFBs based on trimetallic coordination cluster compounds: [Ru2M(μ3-O)(CH3CO2)6(py)3] (M = Ru, Mn, Co, Ni, Zn). The all-ruthenium complex exhibited stable battery cycles in anolyte-catholyte symmetric operation, with rarely observed multielectron storage in a single molecule. Moreover, the complex holds modularly tunable synthetic handles for systematic improvements in solubility and redox potentials. An optimized battery stack containing [Ru3(μ3-O)(CH3CO2)6(py)3]+ anolyte and [Ru2Co(μ3-O)(CH3CO2)6(py)3] catholyte yielded stable cycles with a discharge voltage of 2.4 V, comparable to the state-of-the-art nonaqueous RFBs. Explanation for the exceptional stability of the charged states and prediction of systematic tunability of the redox potentials of the cluster compounds were assisted by DFT calculations.
Bibliographical noteFunding Information:
This work was financially supported by the Basic Science Research Program through the National Research Foundation (NRF) of Korea (NRF-2020R1C1C1007409, NRF-2020R1A4A1017737, NRF-2020R1A2C2007468, and NRF-2020R1C1C1008886)
© 2022 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Biomedical Engineering
- Materials Science(all)