Layered double hydroxide as electrode material for high-performance supercapattery

Abstract

With the increase of population, the demand for a sustainable and green energy source is increasing. To eradicate the energy crisis not only a sustainable energy source is necessary but also an efficient method to store the generated energy is required. Supercapattery is an energy storing system with outstanding energy storage performance. To prepare efficient storage systems, such as supercapattery, the chief requirement is to prepare effective electrodes. Layered double hydroxides (LDH), due to their tunable composition, structure, and morphology, are interesting materials for fabricating efficient electrode material for supercapattery. LDH are a class of synthetic clay with cationic layers comprising anions in the hydrated interlayer. LDH can be prepared through direct or indirect routes. Transition metal oxides/hydroxides, due to their faradic mechanism, provide better capacity and enhanced stability and are found as promising candidates to be used as LDH materials. Ni–Co-LDH and Ni–Mn-LDH are some of the examples. The morphology of these layered structures also plays an important role in enhancing the performance. To enhance the performance efficiency of the LDH-based supercapacitors, various structural, morphological, and compositional alterations can be made. Structures include core–shell provide advantages, such as enhanced electron mobility at electrodes and a sufficient space for deposition of active materials. Besides different structural modifications, LDH with different carbon materials can also be considered for enhancing performance of these layered structures. Overall, this chapter is prepared in such a way that the reader can gain an extensive view of the efficacy of LDH for supercapattery. This chapter gives an overview of the energy storage mechanism in LDH, various synthesis routes, and the different possible structural and morphological alterations that can be made to improve the performance efficiency of the LDH-based supercapacitors.