Recent Advances in the Synthesis and Energy Applications of 2D MXenes

MXenes as a new category of 2D materials have caused a particularly large impact in numerous fields of scientific research and technical applications in recent years. Their open 2D structure and excellent electronic conductivity provide many electrochemically active sites and rapid electron‐transfer paths for reversible Faradic reaction and then render them promising electrode materials for electrochemical energy storage. They offer outstanding volumetric capacitance in supercapacitors and excellent rate capability in rechargeable batteries. Numerous efforts have been made in the past several years. However, research on MXenes has just begun. This review aims to offer useful guidance for the synthesis of high‐quality MXene materials and promote their practical energy applications in supercapacitors, lithium‐ion batteries, and beyond lithium‐ion batteries. A brief discussion of the challenges and opportunities for future research on MXenes is finally presented. The state‐of‐the‐art achievements, challenges, and opportunities of MXene materials and their derivatives are discussed, including synthesis strategies and electrochemical energy‐storage applications in supercapacitors, lithium‐ion batteries, and beyond lithium‐ion batteries. The fundamental science behind the challenges and potential solutions toward a long calendar life and a high energy‐power density is discussed in detail.