Nanocubes of Mo₆S₈ Chevrel phase as active electrode material for aqueous lithium-ion batteries

Abstract

The development of intrinsically safe and environmentally sustainable energy storage devices is a significant challenge. Recent advances in aqueous rechargeable lithium-ion batteries (ARLIBs) have made considerable steps in this direction....

Accumulative Delocalized Mo 4d Electrons to Bound the Volume Expansion and Accelerate Kinetics in Mo6S8 Cathode for High-Performance Aqueous Cu2+ Storage

“…The chemical composition and valence states of Mo 6 S 8 were further investigated by XPS (Figure S2). For the fine Mo 3d spectrum (Figure h), the peak at 226.1 eV corresponds to S 2s, and two asymmetric doublets located at 228.1/231.2 eV and 229.2/232.3 eV are attributed to Mo 3+ and Mo 2+ , respectively. , The presence of Mo 6+ (peaks positioned at 232.8 and 235.8 eV) could be ascribed to slight surface oxidation of the sample due to air contact. The high-resolution S 2p spectra can be fitted into three doublets at 160.8/162.0 eV, 161.8/163.0 eV, and 163.5/164.6 eV, which are assigned to 3-coordinated S 2– , 4-coordinated S 2– , and nonstoichiometric sulfur atoms from the extreme surface (Figure i). , In addition, the Raman spectrum of the Mo 6 S 8 sample (Figure S3) shows five obvious peaks at 136, 233, 316, 376, and 404 cm –1 , which are attributed to the various vibrational phonons of Mo/S and further confirm the well-established preparation of Mo 6 S 8 …”

“…Benefiting from the Cu 2+ (de)­intercalation electronic structure evolution, Mo 6 S 8 demonstrates the best discharge specific capacity and is superior to other Mo 6 S 8 cathode-based secondary ion batteries in the literature, such as aluminum ion batteries (AIBs), magnesium ion batteries (MIBs), zinc ion batteries (ZIBs), sodium ion batteries (SIBs), and lithium-ion battery (LIB) systems (Figures f and S23–S25). ,,− …”

“…For the fine Mo 3d spectrum (Figure 1h), the peak at 226.1 eV corresponds to S 2s, and two asymmetric doublets located at 228.1/231.2 eV and 229.2/ 232.3 eV are attributed to Mo 3+ and Mo 2+ , respectively. 31,32 The presence of Mo 6+ (peaks positioned at 232.8 and 235.8 eV) could be ascribed to slight surface oxidation of the sample due to air contact. The high-resolution S 2p spectra can be fitted into three doublets at 160.8/162.0 eV, 161.8/163.0 eV, and 163.5/164.6 eV, which are assigned to 3-coordinated S 2− , 4-coordinated S 2− , and nonstoichiometric sulfur atoms from the extreme surface (Figure 1i).…”

Chevrel phases: synthesis, structure, and electrocatalytic applications

“…To direct the forthcoming studies on CPs, a prospect is provided as follows: At first, the synthesis technique of CPs requires upgrading to better align with electrocatalytic applications, such as nanoscaling, increasing specific surface area, and tailoring electronic structure. [132][133][134] Secondly, the electrocatalytic performance of CPs should be appropriately correlated with the implanted transition-metal cations into structural cavities, which would in situ occur and alter the redox behavior of active sites. 133 Comparing the structure-activity relationships in various CPs is also beneficial to comprehend the correlations between the active sites and catalytic activity.…”

Elucidating the cation hydration ratio in water-in-salt electrolytes for carbon-based supercapacitors

“…[21][22][23] Based on the design of solvated structural ions, a type of novel aqueous electrolyte with a wide ESW, named ''Water-in-Salt (WIS)'', has been proposed and has been successfully used in batteries, SCs, and other fields. [24][25][26][27][28] The aqueous electrolyte is divided into salt-in-water (SIW, complete the primary solvation shell), salt-water (SW, just complete the primary solvation shell) and water-in-salt (WIS, incomplete the primary solvation shell). 29 For WIS electrolytes, it is found that the wide ESW of electrolytes mainly comes from the formation of a special electrolyte liquid phase structure and an aqueous solid electrolyte interphase, in which the primary shell of cations in the electrolyte plays a core role.…”