A Superior Lithium-Ion Capacitor Based on Ultrafine MnO/Dual N-Doped Carbon Anode and Porous Carbon Cathode

Owing to the unique virtues of specific energy/power densities, lithium-ion capacitors (LICs) have been increasingly attracting research attention. However, the LICs are greatly restrained by the slow Li+-reaction kinetics of battery-type anodes, which is still a challenging task. In this work, we construct a superior LIC using ultrafine MnO/dual N-doped carbon (MnO/DNC) anode and activated N-doped porous carbon (ANC) derived from a homologous polypyrrole precursor. The uniform MnO ultrafine particles (~10 nm size) are well encapsulated into a dual-carbon framework, which provides fast ion/electron transportation and structural cushion for high-rate and long-durable energy storage. Accordingly, the anodic MnO/DNC achieves an impressive rate performance (179 mAh g−1 @10 A g−1) and a stable 500-cycling lifespan. The as-constructed LICs could deliver a large specific energy of 172 Wh kg−1 at 200 W kg−1 and retain at 37 Wh kg−1 even at a high specific power of 15 kW kg−1. It is believed that the design strategy of confining ultrafine conversion-type anode materials into a dual-carbon structure will expedite the development of advanced LICs.