Recent advances of emerging oxyhydroxide for electrochemical energy storage applications

With increasing energy demands and the growing adaptation of green transportation and grid storage, energy storage devices face increasing demands and challenges. As a new generation of materials, oxyhydroxide (MOOH) has attracted increasing attention due to their unique electronic structures, variable valence states, and ultra-high theoretical energy storage capacity. Here, we discuss the advantages and current achievements of MOOH (M = Fe, Co, Ni, Mn, V, and Al) in electrochemical energy storage (EES) devices, including supercapacitors (SCs), lithium-ion batteries (LIBs), and sodium-ion batteries (SIBs). Modification strategies of MOOH hold particular promise for EES. We provide a detailed summary and discussion of nanostructure design, defect engineering, and composite engineering, which provide new avenues to overcome the existing limitations of MOOH materials. Additionally, we believe that innovations in material modification and understanding their applicability to various energy storage needs warrant further exploration. Finally, we proposed a short conclusion and outlook, along with current challenges and prospects of MOOH in the field of energy storage.