Solvothermal Synthesis and Pyrolysis Toward Heteroatom‐Doped Carbon Microspheres for Zinc‐Ion Hybrid Capacitors

Abstract Heteroatom‐doped porous carbon materials have investigated to promote the energy density of zinc‐ion hybrid capacitors (ZICs). Yet, the quest for high‐performance carbon materials or cathodes brings to light the question of which dopants facilitate fast energy storage kinetics and various types of pseudocapacitive reactions. Investigation of carbon materials with precise quantitative dopants as the key variable represents an effective appropriate approach to comprehending the intricate role of dopants in energy storage areas. Here, a straightforward solvothermal strategy is demonstrated for a variety of pristine and iron‐incorporated polymer microspheres, used as precursors for durable spherical carbons intended for cathode applications in ZICs. The strategy effectively governs the incorporation of dopants within the carbon materials, whilewhile maintaining consistent morphology, microtexture, and pore structure across different carbon variations. The synergistic effect of various dopants enhance the pseudocapacitance and facilitate the ion storage process. In consequence, the optimal cathode delivers considerable capacity (178.8 mAh g −1 at 0.5 A g −1 ), good energy density (120.2 Wh kg −1 at 336 W kg −1 ), and excellent cycling stability (101.5% capacity retention at 35 000 cycles). The demonstration showcases a viable method for crafting carbon materials with precise dopants to accommodate the zinc anode, thus enabling high‐capacity and high‐energy ZICs.