Expediting the Conversion of Li₂S₂ to Li₂S Enables High-Performance Li–S Batteries

Abstract

The solid−solid conversion of Li 2 S 2 to Li 2 S is a crucial and rate-controlling step that provides one-half of the theoretical capacity of lithium−sulfur (Li−S) batteries. The catalysts in the Li−S batteries are often useless in the solid−solid conversion due to the poor contact interfaces between solid catalysts and insoluble solid Li 2 S 2 . Considering that ultrafine nanostructured materials have the properties of quantum size effects and unconventional reactivities, we design and synthesize for the pomegranate-like sulfur

Rational Design of the Lotus‐Like N‐Co2VO4‐Co Heterostructures with Well‐Defined Interfaces in Suppressing the Shuttle Effect and Dendrite Growth in Lithium–Sulfur Batteries

“…Furthermore, all the cathodic and anodic currents demonstrate a linear relationship with the square root of the scan rate(Figure S5a,c, Supporting Information), and the lithium diffusivity can be calculated by the Randles-Sevick equation (Equation S2, Supporting Information). [40] The Li + diffusivity largely hinges on the viscosity of the electrolyte with LiPSs and the deposition of insulating Li 2 S/Li 2 S 2 on the electrode. As shown in Figure S5d (Supporting Information) in the peak C1, C2, and A, the Li-ion diffusion coefficient of the N-Co 2 VO 4 -Co/PP cell are 7.52, 5.3, and 10.3 × 10 −7 cm 2 s −1 , respectively.…”

Facile “Lotus Blooming” Strategy to Synthesize a 3D Carbon Nanosheet/Carbon Nanotube Framework with Embedded Co Nanocrystals for High-Performance Lithium–Sulfur Batteries

“…First, the PAA-NH 4 NSs with a grid structure are prepared according to a previous report. 39 Then, CoCl 2B) suggests that CNTs and CNSs are tightly combined, most fine Co nanocrystals are evenly dispersed on CNSs, and a small amount of Co nanocrystals that catalyze the growth of CNTs remain on the top of them. In the HRTEM image of Co nanocrystals (inside Figure 2B), there are clear lattice fringes (0.206 nm) corresponding to the (111) crystal plane of elemental Co. 41 It can be seen from Figure 2C (partially enlarged view of Figure 2B) that there is no apparent interface between CNTs and CNSs, which further proves that they are closely integrated.…”

A hierarchically porous TiO2@C membrane with oxygen vacancies: a novel platform for enhancing the catalytic conversion of polysulfides

“…Similarly, the initial potential of the galvanostatic charge voltage profile is strongly associated with the depth of discharge. 47 Compared with the TiO 2 @C membrane electrode and C membrane electrode, the TiO 2−x @C membrane electrode possesses the lowest initial charging potential of about 2.14 V (Fig. 6b), suggesting the promoted conversion of lithium polysulfides to lithium sulfides.…”