Layered double hydroxides–polymer matrix composites: nexus materials for energy storage applications

In order to overcome burgeoning energy demands along with the ecological crisis caused by dwindling amounts of fossil fuel and increasing levels of carbonaceous emission, there is an immediate need to develop economical, eco-friendly systems for energy applications. To overcome this issue, use of non-carbon materials has been suggested, but their commercial usage is limited due to intermittency and high operational costs. Currently, layered double hydroxides (LDHs) are prospective contenders for energy applications by virtue of unique physicochemical properties and excellent theoretical specific capacitance. Additionally, LDH–polymer matrix composites (PMCs) have also emerged as nexus materials in energy storage sector since they surpass disadvantages of both LDHs and polymers and broaden the horizons for their practical applications. The current review highlights applications of LDH–PMCs as supercapacitors in terms of maximum specific capacitance, energy density, power density, and rate capability along with insights into mechanism of capacitance, thereby outlining their utility in energy storage.