Lewis acidity/basicity of inorganic interlayers as a descriptor for inhibition of charge shuttling in DMPZ-based organic batteries

A disadvantage of organic battery electrode materials is their solubility in battery electrolytes, leading to the shuttle effect. One solution is to use an additional separator, the interlayer, to inhibit charge shuttling of the solubilized species. The work here aims to identify the interlayer material's properties critical to reducing the shuttle effect so as to provide some guidance on interlayer material selection. Using various alumina as interlayer materials in batteries with N,N′-dimethylphenazine (DMPZ) as cathode material, surface charge can be identified as the critical descriptor to inhibiting DMPZ shuttling, more so than morphological properties. Specifically, the interlayer material can be selected for shuttling prevention in the same way as how one chooses chromatography stationary phase for analyte retention. Based on further characterizations, short- and long-term shuttling inhibition can be attributed to the interlayer and the solid-electrolyte interface formed in situ, respectively.