Novel electrochemical capacitors with high-energy density using intercalated metal-organic framework electrodes

The energy-density improvement of capacitors while maintaining high power, long-term-cycle stability and safety is challenging. Asymmetric capacitors using non-faradaic and intercalation electrodes are proposed in order to achieve this. However the reported asymmetric capacitors with graphite-based negative electrode have a safety risk, which is an internal short circuit due to Li deposition when further high-energy density is performed. Here asymmetric capacitors consisting of intercalated metal-organic frameworks (iMOFs) negative operating potential range of 0.5-1.0 V vs. Li/Li⁺ that enable Li deposition reduction and activated carbon positive electrodes is proposed to construct a high volumetric energy (ca. 60 Wh L^-1) and power densities with safety.