Coordination engineering of single zinc atoms on hierarchical dual-carbon for high-performance potassium-ion capacitors.
J Colloid Interface Sci 2023;
649:203-213. [PMID:
37348340 DOI:
10.1016/j.jcis.2023.06.038]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Dual-carbon engineering combines the advantages of graphite and hard carbon, thereby optimizing the potassium storage performance of carbon materials. However, dual-carbon engineering faces challenges balancing specific capacity, capability, and stability. In this study, we present a coordination engineering of Zn-N4 moieties on dual-carbon through additional P doping, which effectively modulates the symmetric charge distribution around the Zn center. Experimental results and theoretical calculations unveil that additional P doping induces an optimized electronic structure of the Zn-N4 moieties, thus enhancing K+ adsorption. A single-atom Zn metal coordinated with nitrogen and phosphorus reduces the K+ diffusion barrier and improves fast K+ migration kinetics. Consequently, Zn-NPC@rGO exhibits high reversible specific capacities, excellent rate capability, and impressive cycling stability, and remarkable power and energy densities for potassium-ion capacitors (PICs). This study provides insights into crucial factors for enhancing potassium storage performance.
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