A new trick for an old technology: Ion exchange syntheses of advanced energy storage and conversion nanomaterials

Electrochemical energy storage and conversion devices have greatly advanced our daily life in the past few decades because of the convenience and flexibility they provide. As one of the essential components of energy storage and conversion devices, electrode materials play a crucial role in overall device performances. Conventional material preparation methods, including hydrothermal, chemical vapor deposition, high temperature solid phase methods, etc., are often subject to harsh preparation conditions. Therefore, much simpler and more efficient preparation methods are still sought after by the research community. In recent years, ion exchange (IE) technology, as a novel method for syntheses of nanomaterials, has attracted a great deal of research attention for its great capability in precise structural design and simultaneous regulation of component compositions. Nevertheless, the links among reaction mechanisms, resulting products, and product application performances, have not been fully elaborated. Herein, this review systematically summarizes historical developments of the IE technology for preparation of nanomaterials and relevant reaction mechanisms from both kinetic and thermodynamic perspectives. A detailed summary of recent applications of the IE technology for preparation of a wide variety of nanomaterials and their applications in electrochemical energy storage and conversion devices, including supercapacitors, lithium/sodium-ion batteries, electrolytic water splitting, and hydrogen fuel cells, is presented. In-depth understanding of the IE technology provides better technical approaches for fabrication of high-performance electrode materials. In the final section, an outlook on the IE technology is offered.