Progress in secondary battery research

The storage and utilization of energy is one of the important topics in the development of science and technology, especially regarding secondary batteries, which are efficient electrical-/chemical-energy-converting devices. This review systematically introduces the important research progress made in the context of secondary batteries, starting from their development and leading to the introduction of related basic theoretical knowledge. The current research on secondary batteries that are based on different systems and related key materials is discussed in detail, and includes lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, magnesium-ion batteries, zinc-ion batteries, calcium-ion batteries, aluminum-ion batteries, fluorine-ion batteries, chloride-ion batteries, dual-ion batteries, lithium-sulfur (Se) batteries, sodium-sulfur (Se) batteries, potassium-sulfur (Se) batteries, polyvalent metal-sulfur-based batteries, lithium-oxygen batteries, sodium-oxygen batteries, potassium-oxygen batteries, aqueous metal-ion batteries, polyvalent metal-oxygen batteries, lithium-bromine (or lithium-iodine) batteries, photo-assisted batteries, flexible batteries, organic batteries, and metal-carbon dioxide batteries. Additionally, the common characterization techniques for electrode reaction processes in battery research are also introduced, including cryo-electron microscopy, transmission electron microscopy, synchrotron radiation, in situ spectroscopic techniques, and magnetic characterization. This paper will help researchers to systematically understand secondary battery technology and provide good guidance for future research on secondary batteries.