PAANa-induced ductile SEI of bare micro-sized FeS enables high sodium-ion storage performance

Abstract

High-capacity metal chalcogenides often suffer from low initial coulombic efficiency (ICE) and serious capacity fading owing to the shuttle effect and volumetric expansion. Various carbon-coating and fixing methods were used to improve the above-mentioned performance. However, the synthesis processes of them are complex and time-consuming, limiting their engineering applications. Herein, polar polymer binder sodium polyacrylate (PAANa) is selected as an example to solve the problems of metal chalcogenides (bare micro-sized FeS) without any modification of the active materials. The special function of the polymer binder in the interface between the active material particles and the electrolytes demonstrates that a PAANa-induced network structure on the surface of ion sulfide microparticles not only buffers the mechanical stress of particles during discharging-charging, but also participates in forming a ductile solid electrolyte interphase (SEI) with high interfacial ion transportation and enhanced ICE. The cyclic stability and rate performance can be simultaneously improved. This work not only provides a new understanding of the binder on electrode, but also introduces a new way to improve the performance of batteries.

Binary Iron Sulfide as a Low-Cost and High-Performance Anode for Lithium-/Sodium-Ion Batteries

“…For the first cathodic scan, a weak reduction peak at ∼1.2 V is observed and can be correlated to the Na + -intercalation into FeS x to form Na x FeS x . A sharp peak appearing at 0.72 V shows relatively low repeatability in the following cathodic sweeps, which can be attributed to the formation of a solid-electrolyte interface (SEI). , In addition, the broad peak in the range of 0.1–0.5 V corresponds to the subsequent conversion reaction of Na x FeS x and the further alloying reaction of metallic Fe 0 and byproduct Na 2 S . During the corresponding anodic scan, the apparent peak at ∼1.4 V suggests a reverse conversion reaction between metallic Fe 0 and Na 2 S .…”

“…54 A sharp peak appearing at 0.72 V shows relatively low repeatability in the following cathodic sweeps, which can be attributed to the formation of a solidelectrolyte interface (SEI). 55,56 In addition, the broad peak in the range of 0.1−0.5 V corresponds to the subsequent conversion reaction of Na x FeS x and the further alloying reaction of metallic Fe 0 and byproduct Na 2 S. 15 During the corresponding anodic scan, the apparent peak at ∼1.4 V suggests a reverse conversion reaction between metallic Fe 0 and Na 2 S. 54 The almost overlapped CV curves of the following four cycles indicate the stable structure of the composite. The first two cycles of discharge/charge profiles of the FeS 2 /Fe 7 S 8 -rGO cell are shown in Figure 6b.…”

Achieving long-cycling sodium-ion full cells in ether-based electrolyte with vinylene carbonate additive

“…Sodium-ion batteries (SIBs) are considered as one kind of the most promising candidates for large-scale energy storage applications. Their electrode materials have been widely developed in recent years [1][2][3][4][5][6][7] in which some materials have demonstrated delightful performance meeting the application requirements in some extent, such as phosphates and prussian blue for cathode materials, and hard carbon and chalcogenides for anode materials [8][9][10][11][12][13][14][15]. However, the wicked compatibility of electrolyte between cathodes and anodes leading to the disappointing performance of the assembled full cells, though it is crucial to the practical application of SIBs.…”

Preparation and Study of a Simple Three-Matrix Solid Electrolyte Membrane in Air

“…The cycling stability of the LNMO/SPLL/Li batteries is evaluated at a current density of 0.25 C. As shown in Figure 8 , the battery can reach up to 117.5 mAhg −1 in the first cycle. After 500 cycles, the capacity can still reach 85.6 mAhg −1 with a capacity retention rate of 82.5% [ 33 ]. For such a good performance, we attribute it to several aspects.…”