Dual‐Carbon Lithium‐Ion Capacitors: Principle, Materials, and Technologies

Abstract Lithium‐ion capacitors (LICs) optimize energy density and power capability of lithium‐ion batteries (LIBs) and electric double layer capacitors (EDLCs). The most promising LICs are those, called dual‐carbon LICs, using the LIB carbonaceous negative electrode and EDLC activated carbon positive electrode due to the low lithiation‐delithiation potential of carbonaceous materials and the excellent stability of activated carbon at high potentials. However, a pre‐lithiation process is required to enable such LICs because both the carbonaceous materials used do not contain Li + ions. In this mini‐review, the principle and materials of the dual‐carbon LICs are outlined, and the key technologies are critically assessed.