Engineered phase of nickel sulfides inside hairy hollow fibers towards high-performance anodes for flexible potassium ion hybrid capacitors

Abstract

The development of potassium-ion hybrid capacitors (PIHC) is restricted by the cathode/anode kinetics mismatch and the limited working environments. Herein, a freestanding fiber assembled by tiny carbon nanotube capped with...

Crystal phase of nickel sulfide dictates hydrogen evolution activity of various semiconducting photocatalysts

“…The peaks located at ∼853 eV and ∼870 eV can be attributed to Ni 2+ , while those located at ∼856 eV and ∼874 eV can be assigned to Ni 3+ . The appearance of Ni 3+ may be owing to the surface oxidation of S. 40,41 For S 2p spectra, the peaks for Ni–S, S 2p 3/2 , S 2p 2/3 and S–O can also be detected, further supporting the successful synthesis of NiS x .…”

Carbon-based flexible electrodes for electrochemical potassium storage

“…Zhang and co-workers designed tiny carbon nanotubes capped with nickel sulfide nanocrystallites (NSCN hollow fiber). [98] The authors investigated the physicochemical properties of three nickel sulfide nanocrystallites with different phases (α-NiS, β-NiS, and NiS2) inside the NSCN fiber. Both theoretical and experimental results indicated that α-NiS had the best kinetics and durability.…”

“…Over 75% of the discharge plateau located below 0.25 V endowed the HCMB//Activated carbon full cell with a high operating working voltage (4. [98] (Reprinted with permission, Copyright 2022, The Royal Society of Chemistry). (g) Demonstrations of tissue and the HCMB paper at different bending states.…”

Dimensional engineering of anode materials for high performance potassium ion hybrid capacitor—A review

“…Generally speaking, good dimensional structures discussed above can be divided into 1D, two‐dimensional (2D), three‐dimensional (3D), and zero‐dimensional (0D) PIHC anode materials. Different dimensions have different influences on the properties of PIHC electrode materials, as shown in the following: 1D materials: (a) Liner nanostructures can provide a convenient ion electron pathway to promote the fast Faraday reaction of hybrid composite electrode 32 ; (b) High aspect ratio geometry enables 1D materials to be crosslinked into different high‐dimensional networks; (c) Simplicities of defects importing and heteroatom doping make it porous or hollow to enlarge the specific surface area, and increase the amount of in‐situ catalytic sites 33 . 2D materials: (a) Layered structures provide an efficient channel for the rapid transport of potassium ions and electrons during the repeated cycle 34 ; (b) Thin inorganic solid electrolyte interface (SEI) phase can be formed in the layered structure of electrolyte, which is beneficial to interface stability and reaction kinetics 35 ; (c) Significant interfacial effects enhance ion adsorption and promote electrochemical kinetics 36 .…”

“…Different dimensions have different influences on the properties of PIHC electrode materials, as shown in the following: 1D materials: (a) Liner nanostructures can provide a convenient ion electron pathway to promote the fast Faraday reaction of hybrid composite electrode 32 ; (b) High aspect ratio geometry enables 1D materials to be crosslinked into different high-dimensional networks; (c) Simplicities of defects importing and heteroatom doping make it porous or hollow to enlarge the specific surface area, and increase the amount of in-situ catalytic sites. 33 2D materials: (a) Layered structures provide an efficient channel for the rapid transport of potassium ions and electrons during the repeated cycle 34 ; (b) Thin inorganic solid electrolyte interface (SEI) phase can be formed in the layered structure of electrolyte, which is beneficial to interface stability and reaction kinetics 35 ; (c) Significant interfacial effects enhance ion adsorption and promote electrochemical kinetics. 36 3D materials: (a) Shorter ion transfer paths enable good cyclic stability in high performance PIHC devices 37 ; (b) Self-supporting nanostructures buffer the material volume changes during potassiation/ depotassiation and attract additional pseudocapacitance 38 ; (c) Porous characteristic offers larger specific surfaces area with rich active sites, which is where potassium ion storage dynamics with excellent performance provided.…”