Deciphering carbon dots in a new perspective from structural engineering to mechanisms in batteries

Carbon dots (CDs), as emerging members of the carbon nanomaterial family with ultra-small sizes and unique physicochemical properties, which has attracted a great deal of attention in energy conversion and storage, especially in rechargeable batteries in recent years. Although CDs have shown remarkable potential in different batteries, the mechanism of its role for solving common problems in batteries is lacking. In this review, we first clarify the constitutive relationship between the preparation, modification and electrochemical properties of CDs and provide strategies for structural design. Notably, we categorize the role of CDs in batteries from a new perspective, detailing the mechanism that CDs function in different electrochemical properties. Finally, we provide several issues facing CDs in battery applications and directions for further research. This review is expected to serve as an insightful guidance for scientists who work with the fascinating material of CDs and to stimulate further exploration in energy storage.