Binding Se into nitrogen‐doped porous carbon nanosheets for high‐performance potassium storage

Abstract

Selenium cathode has been demonstrated as a promising candidate of cathode material for low‐cost and high‐energy density potassium ion batteries (PIBs). Nevertheless, their applications are prevented by poor electrochemical performance due to the shuttle effect of high‐order polyselenides, the sluggish diffusion of bigger K+, and the huge volumetric expansion during cycling. In this work, we design a multifunctional Se host (N‐HCNS) by grafting ZIF‐8‐derived microporous carbon onto the surface of N‐doped porous carbon nanosheets. The obtained N‐HCNS carbon matrix integrates conductivity, captivity, and immobility abilities, which inhibits the polyselenides shuttle, improves the Se utilization, and buffers the volume change during cycling. The 3D hollow carbon skeleton enhances the infiltration of electrolytes. As an cathode for PIBs, the Se@N‐HCNS electrode delivers an unprecedented life‐span (260 mAh g−1 at 1.0 A g−1 after 2000 cycles) and exhibits a remarkable rate capacity (339 mAh g−1 at 5.0 A g−1). Density functional theory (DFT) calculation reveals the effective adsorption of K2Se with pyridine and pyrrole nitrogen doping in carbon matrix. The unique synergetic design of electrode not only gives insight into the reaction mechanism but also highly emphasizes the potential capabilities of N‐doped carbon in K‐Se batteries.

3D Ordered Porous Hybrid of ZnSe/N‐doped Carbon with Anomalously High Na+ Mobility and Ultrathin Solid Electrolyte Interphase for Sodium‐Ion Batteries

“…On the other hand, constructing 3DOHP structure (Figure 2d) combined with N ‐doped carbon is an effective strategy to improve electrochemical performance of electrode materials. [ 27,28 ] The hierarchical pores with thin wall are favorable to reducing the migration routes of ions and improving the rate performance of ZnSe. [ 29 ] Combined with the above theoretical calculation and experimental results, it is expected that the construction of 3DOHP combined with N ‐doped carbon, in addition with the optimization of electrolytes, are helpful to design ZnSe with excellent rate performance and great cycle stability for SIBs.…”

Carbon‐based anode materials for potassium‐ion batteries: From material, mechanism to performance

“…Actually, similar to K‐S batteries, Se could also alloy with K to provide the capacity, denoted as K‐Se batteries with moderate operating voltage. After binding the Se anode into supported carbon nanosheets, the rate performance and cycle stability could be significantly improved 103 …”

Artificial Heterogeneous Interphase Layer with Boosted Ion Affinity and Diffusion for Na/K‐Metal Batteries

“…[ 9–13 ] Among them, the sodium‐metal or potassium‐metal anode (NMA or PMA) has attracted the most attention owning to its high theoretical specific capacity (1165 mAh g –1 for NMA, and 687 mAh g –1 for PMA) and the low potential (−2.71 V vs SHE for Na, and −2.93 V vs SHE for K). [ 14–21 ]…”