Ultra‐High Initial Coulombic Efficiency Induced by Interface Engineering Enables Rapid, Stable Sodium Storage

Abstract

High initial coulombic efficiency is highly desired because it implies effective interface construction and few electrolyte consumption, indicating enhanced batteries life and power output. In this work, ah igh-capacity sodium storage material with FeS 2 nanoclusters ( % 1-2 nm) embedded in N, Sdoped carbon matrix (FeS 2 /N,S-C) was synthesized, the surface of which displays defects-repaired characteristic and detectable dot-matrix distributed Fe-N-C/Fe-S-C bonds.A fter the initial discharging process,t he uniform ultra-thin NaF-rich ( % 6.0 nm) solid electrolyte interphase was obtained, thereby achieving verifiable ultra-high initial coulombic efficiency ( % 92 %). The defects-repaired surface provides perfect platform, and the catalysis of dot-matrix distributed Fe-N-C/Fe-S-Cb onds to the rapid decomposing of NaSO 3 CF 3 and diethylene glycol dimethyl ether successfully accelerate the building of two-dimensional ultra-thin solid electrolyte interphase.D FT calculations further confirmed the catalysis mechanism. As ar esult, the constructed FeS 2 /N,S-C provides high reversible capacity (749.6 mAh g À1 at 0.1 Ag À1 )a nd outstanding cycle stability (92.7 %, 10 000 cycles,1 0.0 Ag À1 ). Especially,a tÀ15 8 8C, it also obtains ar eversible capacity of 211.7 mAh g À1 at 10.0 Ag À1 .A ssembled pouch-type cell performs potential application. The insight in this work provides abright way to interface design for performance improvement in batteries.

Stabilizing V2O3 in carbon nanofiber flexible films for ultrastable potassium storage

“…41,62,63 Additionally, the characteristic D-band (at around 1342 cm −1 ) and G-band (at around 1583 cm −1 ) are related to the defects and disorder of sp 3 carbon atoms and the ordered structure of sp 2 carbon atoms in plane, respectively. [64][65][66] Clearly, the V 2 O 3 /CNF film shows a higher I D / I G ratio (0.93) than C (0.90), indicating that the V-O-C cluster and defects in the carbon layer are intimately linked, which is beneficial for providing a large amount of active sites for the adsorption of K + in the V 2 O 3 /CNF film. In the FT-IR spectrum (Fig.…”

“…75 In the O 1s spectrum, the change of the peak intensity for the peaks of CvO and V-O bonds evidences the decomposition of electrolytes and the formation of solid electrolyte interphase layers on the electrode surface during the discharge and charge process based on the typical peak strength. The solid electrolyte interphase layer is helpful to stabilize the electrode surface, promote the structural and chemical stability of active materials, and ensure rapid K + interdiffusion kinetics on the nanoscale interfaces, 64,[76][77][78] therefore, resulting in advanced potassium storage performance with enhanced reversibility and cycling stability. And the peak of the V-O-C bond retained high intensity even after the charge and discharge process, indicating the V-O-C bond was stable, which is beneficial for maintaining the stability of the local V-O-C cluster structure and enabling a long cycle life for potassium-ion batteries.…”

Molecular Engineering on Solvation Structure of Carbonate Electrolyte toward Durable Sodium Metal Battery at −40 °C

“…In addition, the inorganic component of Na 3 N (398.1 eV) is found, and its ratio in ES6‐BLTE is significantly higher than that in BLTE (Figure S17, Supporting Information), which is because that the ES can promote the decomposition of FSI − [22] . Concerning the S 2p specie, RSO 2 F (169.9/171.1 eV), [23] N−S (168.7/169.7 eV), [24] and SO 3 2− (167.1/168.2 eV), [25] are detected on the SEI surface. After etching, the RSO 2 F disappears, while new matters of Na 2 S (161.9/163.2 eV) and C−S (163.4/164.5 eV) are disclosed.…”

Impregnating ultrafine FeS2 nanoparticles within hierarchical carbon tubes for advanced potassium-ion batteries

“…3e), the peaks at 162.9 and 165.3 eV correspond to S 2p 3/2 of FeS 2 and S 2p 1/2 of doped S, implying the successful synthesis of FeS 2 . 37 The characteristic peak located at 164.1 eV is ascribed to the S 2p 1/2 of FeS 2 and the S 2p 3/2 of doped S. 38 Two other peaks at 168.9 and 170.1 eV are related to sulphates on the surface of the sample. In addition, the XPS spectrum of C 1s shown in Fig.…”