Since its commercialization in 1991, lithium‐ion batteries have been continuously studied to develop its energy density, power capability, and long‐term cycling characteristics. Unlike the earlier lithium‐ion battery based on the intercalation reaction such as LiCoO
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cathode and graphite anode, various materials and reaction mechanisms have been investigated with the development of the technology. Also, in accordance with the improvement of the overall properties, lithium‐ion batteries are also being applied as energy storage systems (ESSs) for renewable energy facilities as well as power systems for electric vehicles (EVs). Moreover, in order to reduce the risk of explosion and to improve the stability of the battery, the electrolytes and separators in lithium‐ion batteries have been widely studied. This article highlights the current trend of the developments on the representative components in lithium‐ion battery.