High-Performance Lithium-Ion Capacitors Produced by Atom-Thick Carbon Cathode and Nitrogen-Doped Porous Carbon Anode

The all-carbon lithium-ion capacitor (LIC) has the advantage of fast ion and electron transmission and is the most promising electrochemical energy storage equipment. Here, we reported a high-performance hybrid all-carbon LIC using an atom-thick carbocoal-derived hierarchical porous carbon (CHPC) cathode and a nitrogen-doped porous carbon (NPC) anode. CHPC and NPC were readily prepared through in situ catalytic activation and pyrolysis of low-cost anthracite and asphalt powder, respectively. The CHPC endows a large BET specific surfaces area of 3160 m2 g–1, a continuous highly curved three-dimensional (3D) network of atomic thickness, and wide pores of 0.95–3.68 nm, which give the CHPC with excellent capacitive merits. Meanwhile, the NPC possesses lots of active adsorption sites and expanded interlamellar space for effective storage and migration of Li+, endowing the rapid kinetics. Hybrid LICs by coupling such CHPC cathode and pre-lithiation NPC anode yielded high gravimetric capacitance (139 mAh g–1cathode at 0.5 A g–1) and energy density (220 Wh kgtotal–1 at a specific power of 805 W kg–1) in organic electrolyte. Furthermore, the process of obtaining atom-thick-wall high-surface-area carbon at low cost is readily scalable.