Current-density dependence of Li₂S/Li₂S₂ growth in lithium–sulfur batteries

Abstract

The current-density-dependent Li2S1/2 nucleation/growth was explored and this guiding principle was applied for the construction of high-efficiency Li–S batteries.

A Highly Conductive MOF of Graphene Analogue Ni3(HITP)2 as a Sulfur Host for High‐Performance Lithium–Sulfur Batteries

“…The results indicated that traditional MOF hosts could hardly reach the expectation for high-performance Li-S batteries even if a long-range conductive agent of CNT was used to replace traditional conduction agents. Based on the "triple-phase boundary" theory, [48,49] the adsorbed sulfur species would accumulate around the polar sites if there were no conductive supports next to them. Because conductive supports can help to construct triple-phase boundaries for the "transfer" and "conversion" of polysulfides.…”

“…Because conductive supports can help to construct triple-phase boundaries for the "transfer" and "conversion" of polysulfides. [48] For nonconductive MOFs, electrons could not easily reach the adsorption sites and the adsorbed polysulfides would become a "dead" sulfur source which might not participate in the following redox reactions. Moreover, nonuniform deposition of Li 2 S 2 /Li 2 S on the surface of conductive substrate would occur, leading to a worse cycling performance.…”

Ultrafine Co3Se4 Nanoparticles in Nitrogen‐Doped 3D Carbon Matrix for High‐Stable and Long‐Cycle‐Life Lithium Sulfur Batteries

“…During the first discharge stage, from onset‐potential to 1.7 V, the carbon hosts became thicker mainly due to the deposited Li 2 S 2 /Li 2 S on the surface. While during the subsequent charge process, the thickness of this layer was decreased, attributing to the oxidation of Li 2 S 2 /Li 2 S to S. [ 16,56 ] The uniform distribution of Li 2 S 2 /Li 2 S on the surface of carbon networks highlights the catalytic effects of N‐CN‐750@Co 3 Se 4 ‐0.1 m . Figure 7b shows the ex situ XRD patterns of these disassembled cathodes.…”

“…: 23–0319) could be detected at the very beginning and became more and more remarkable, indicating the rapid and complete conversion of sulfur species to Li 2 S. On the contrary, the Li 2 S diffraction peak would weaken in the charge process and finally disappeared, whereas weak Co 3 Se 4 diffraction peaks emerged in the meantime, which could be attributed to the decomposition of Li 2 S and the formation of amorphous S on the surface. [ 16 ] Almost all of these deposited Li 2 S 2 /Li 2 S were converted to S. The complete transformation between S and Li 2 S suggests high sulfur utilization and rapid reaction kinetics. Rationally designed N‐CN‐750@Co 3 Se 4 ‐0.1 m sulfur host with conductive and catalytic Co 3 Se 4 nanoparticles grafting on our interconnected carbon networks is highly desirable for high‐performance LSBs.…”

“…On the other side, hierarchical pores of sulfur hosts can physically confine sulfur intermediates and increase void spaces in hosts to alleviate large volume variations during charge/discharge process. [ 16–19 ] Hence, various kinds of nanostructured carbonaceous materials have been extensively explored. [ 20–22 ] However, most of these carbon matrixes possess few polar sites for incapable of bonding with LiPSs and large amounts of electrolyte are required to fully infiltrate these highly porous electrodes, thus compromising energy densities.…”