Amorphization-induced surface electronic states modulation of cobaltous oxide nanosheets for lithium-sulfur batteries

Abstract

Lithium-sulfur batteries show great potential to achieve high-energy-density storage, but their long-term stability is still limited due to the shuttle effect caused by the dissolution of polysulfides into electrolyte. Herein, we report a strategy of significantly improving the polysulfides adsorption capability of cobaltous oxide by amorphization-induced surface electronic states modulation. The amorphous cobaltous oxide nanosheets as the cathode additives for lithium-sulfur batteries demonstrates the rate capability and cycling stability with an initial capacity of 1248.2 mAh g-1 at 1 C and a substantial capacity retention of 1037.3 mAh g-1 after 500 cycles. X-ray absorption spectroscopy analysis reveal that the coordination structures and symmetry of ligand field around Co atoms of cobaltous oxide nanosheets are notably changed after amorphization. Moreover, DFT studies further indicate that amorphization-induced re-distribution of d orbital makes more electrons occupy high energy level, thereby resulting in a high binding energy with polysulfides for favorable adsorption.

Polysulfide Regulation by Hypervalent Iodine Compounds for Durable and Sustainable Lithium–Sulfur Battery

“…[ 43 ] While in the anodic scan, two contiguous oxidation peaks at 2.35 and 2.4 V are attributed to the oxidation of Li 2 S 2 /Li 2 S to long‐chain soluble LiPSs (Li 2 S n , 4 ≤ n ≤ 8) and oxidation to S 8 . [ 44 ] Since the 2nd cycle, the CV curves indicate excellent electrochemical reversibility with identical redox features. In comparison, the CV curve of CNT/PP shows lower current density and worse reversibility than PhIO@CNT/PP (Figure S15, Supporting Information).…”

Recent Breakthroughs in the Bottleneck of Cathode Materials for Li–S Batteries

“…Thus, the physical and chemical dual adsorption and catalytic the conversion of Co 3 O 4 /CoO/GNS/ h -BN/S for LiPSs could reduce the capacity attenuation of Li–S batteries. In addition, amorphous CoO has a change in structure. Compared with crystalline CoO, the gap between the d band of Co and the p band of LiPSs was lower, so the binding energy between amorphous CoO and LiPSs was stronger, which strengthens the adsorption of LiPSs to further inhibit the shuttle effect (Figure b).…”

“…(b) Cycling performance at 1 C of the S@rGO/a-CoO NSs electrode. Reproduced from ref . Copyright 2021, Li et al, used under Creative Commons CC BY license (), published by Springer Nature.…”

Ultra‐Small Ferromagnetic Fe3O4 Nanoparticles Modified Separator for High‐Rate and Long Cycling Lithium‐Sulfur Batteries

“…Lithium‐sulfur (Li−S) batteries emerged as a promising candidate for next‐generation energy storage systems due to high theoretical energy density (2567 Wh kg −1 ), high theoretical capacity (1675 mAh g −1 ), low cost, and environmental friendliness [1–3] . As portable electronic devices and electric vehicles are becoming ubiquitous, rechargeable batteries with high‐rate and long cycling stability are desired for the energy storage market [4–6] . However, the rate and cycling performance of Li−S batteries are restricted by the insulator nature of sulfur and Li 2 S 2 /Li 2 S, [7,8] serious volume change of sulfur during the redox conversion process, [9] and the shuttle effect [10]…”

“…[1][2][3] As portable electronic devices and electric vehicles are becoming ubiquitous, rechargeable batteries with high-rate and long cycling stability are desired for the energy storage market. [4][5][6] However, the rate and cycling performance of LiÀ S batteries are restricted by the insulator nature of sulfur and Li 2 S 2 /Li 2 S, [7,8] serious volume change of sulfur during the redox conversion process, [9] and the shuttle effect. [10] To overcome the above problems, the current effort is often dedicated to the search for new host materials, including carbon materials, [11][12][13] metal oxides, [14][15][16] metal sulfides, [17,18] and metal nitrides.…”