Preparation of Nickel and Cobalt‐Based Micro–Nano Structural Materials and their Applications in Energy Storage and Conversion

Nickel (Ni) and cobalt (Co) based micro-nano structural materials have emerged as a class of highly promising functional materials in the field of energy storage and conversion due to their unique electronic structures, excellent electrochemical properties, and abundant natural reserves. This review systematically summarizes recent advances in the preparation methods and energy-related applications of Ni and Co-based micro-nano structure materials. Various synthetic strategies are introduced, including hydrothermal methods, solvothermal methods, electrodeposition, template-assisted approaches, and other emerging techniques, with particular emphasis on the precise control of morphology, composition, and microstructure. The review then comprehensively discusses their applications in key energy technologies such as lithium-ion batteries, sodium-ion batteries, supercapacitors, oxygen evolution reaction, hydrogen evolution reaction, and oxygen reduction reaction. For each application, the fundamental working mechanisms are analyzed, and how the micro-nano structures' performance enhancement are highlighted. Finally, current challenges and provide perspectives on future research directions, including scalable production, performance optimization, and advanced characterization, are outlined. This review aims to provide valuable insights for the rational design of high-performance Ni and Co-based materials for next-generation energy applications.