Extraordinarily stable and wide‐temperature range sodium/potassium‐ion batteries based on 1D SnSe₂‐SePAN composite nanofibers

Abstract

Developing electrodes with long lifespan and wide‐temperature adaptability is crucial important to achieve high‐performance sodium/potassium‐ion batteries (SIBs/PIBs). Herein, the SnSe2‐SePAN composite was fabricated for extraordinarily stable and wide‐temperature range SIBs/PIBs through a coupling strategy between controllable electrospinning and selenylation, in which SnSe2 nanoparticles were uniformly encapsulated in the SePAN matrix. The unique structure of SnSe2‐SePAN not only relieves drastic volume variation but also guarantees the structural integrity of the composite, endowing SnSe2‐SePAN with excellent sodium/potassium storage properties. Consequently, SnSe2‐SePAN displays a high sodium storage capacity and excellent feasibility in a wide working temperature range (−15 to 60°C: 300 mAh g−1/700 cycles/−15°C; 352 mAh g−1/100 cycles/60°C at 0.5 A g−1). At room temperature, it delivers a record‐ultralong cycling life of 192 mAh g−1 that exceeds 66 000 cycles even at 15 A g−1. It exhibits extremely superb electrochemical performance in PIBs (157 mAh g−1 exceeding 15 000 cycles at 5 A g−1). The ex situ XRD and TEM results attest the conversion‐alloy mechanism of SnSe2‐SePAN. Also, computational calculations verify that SePAN takes an important role in intensifying the electrochemical performance of SnSe2‐SePAN electrode. Therefore, this study breaks new ground on solving the polyselenide dissolution issue and improving the wide temperature workable performance of sodium/potassium storage.

In Situ Encapsulation of MoSxSe2–x Nanocrystals with the Synergistic Function of Anion Doping and Physical Confinement with Chemical Bonding for High-Performance Sodium/Potassium-Ion Batteries with Wide Temperature Workability

“…Raman spectra and Fourier transform infrared (FTIR) spectra disclosed the typical structures of MoS x Se 2– x -SePAN and SePAN compounds, as revealed in Figure b,c. All compounds depict typical D and G bands because of the breathing mode of sp 3 and sp 2 hybridization of C–C. , The A 1g mode of MoS 0.25 Se 1.75 -SePAN appears at 219.5 cm –1 , implying the presence of Mo–Se bond in the MoS x Se 2– x -SePAN sample. , In addition, another peak near 194.6 cm –1 represents the C–Se bond of SePAN and an additional signal at 231.7 cm –1 refers to Se n . To acquire the chemical bonds of MoS x Se 2– x -SePAN, we carried out FTIR spectroscopy.…”

“…51,52 The A 1g mode of MoS 0.25 Se 1.75 -SePAN appears at 219.5 cm −1 , implying the presence of Mo−Se bond in the MoS x Se 2−x -SePAN sample. 50,53 In addition, another peak near 194.6 cm −1 represents the C−Se bond of SePAN and an additional signal at 231.7 cm −1 refers to Se n . 54 To acquire the chemical bonds of MoS x Se 2−x -SePAN, we carried out FTIR spectroscopy.…”

Defect and interlayer spacing engineering of vanadium selenide for boosting sodium-ion storage

“…Vanadium selenide (VSe 2− x ) has aroused widespread interest due to their large interlayer spacing for sufficient sodium-ion intercalation and high conductivity for fast electron transport. 15–22 In addition, the distinctive multielectron transfer in VSe 2− x enables high theoretical capacity and large energy density. 23 Nevertheless, the exploitation of high-performance SIB anodes based on 2D VSe 2− x still remains a daunting challenge.…”

Elaborate tree-like Cu–Ag clusters from green electrodeposition for efficiently electrocatalyzing CO2 conversion into syngas

“…Among various carbon dioxide (CO 2 ) conversion methods, the electrocatalytic CO 2 reduction reaction (CO 2 RR) has received extensive attention because it is green and clean, has mild operating conditions and allows easy adjustment of the selectivity for different products by applying different potentials. [1][2][3][4][5][6] However, the CO 2 RR often requires a high overpotential due to the lack of suitable electrocatalysts that can overcome the high activation energy barrier of CO 2 reduction, resulting in a low energy utilization efficiency for electrocatalysis. [7][8][9][10] Therefore, exploiting electrocatalysts with superior catalytic performance is the key to promoting the wide application of electrocatalytic CO 2 RR towards achieving carbon neutrality.…”