Slow electrochemical kinetics and dendrite growth are the main obstacles for lithium-sulfur (Li-S) batteries, and the study of polycrystalline effects requires a better understanding of the design principles of catalysts. Based on this,Associate Professor Xi Baojuan of Shandong University andProfessor Xiong Shenglin et alIn this paper, a systematic evaluation of two crystal forms of Cote2 alloys was reported by sulfur-containing reduction reaction (SRR) and Li-Plating stripping. Orthogonal (O-)Cote2 annihilated hexagonal (H-)Cote2, exhibiting better catalysis and more uniform lithium deposition, and the whole cell made of O-Cote2 was at 0Under the condition of 5 C, it can be stably charged and discharged for 800 times, and the capacity attenuation of each cycle is only 0055% at low electrolyte and high sulfur load 6At 4 mg cm-2, its area capacity reaches 65 mah cm-2。
VASP Interpretation
Through density functional theory (DFT) calculations, the authors studied different Cote2 phases and gained a theoretical understanding of the influence of relative sulfur catalytic chemistry. Among the NG, H-Cote2 and O-Cote2 catalysts, O-Cote2 has the strongest binding ability to different sulfur species. The sulfur host has good adsorption capacity and effectively captures LIPSS, thereby inhibiting the shuttle effect. Therefore, the introduction of O-Cote2 phase is expected to improve the capacity retention rate of Li-S cells.
When the lipss are adsorbed on the electrode surface, the electronic state interaction between the adsorbate and the substrate is analyzed by state density (DoS). The higher the EF position of cobalt ditelluride (CoS2), the higher the anti-bond state shift, and the lower the occupancy, resulting in a stronger interaction between the substrate surface and the adsorbate. In addition, the position of the antibond orbital is determined by the D-band center position of CO on cobalt telluride. The projection of CO atoms on H-CoTe2 and O-CoTe2 after absorbing Li2S (PDOS) was calculated, and the D-band centers of CO atoms on H-Cote2 and O-Cote2 were -1., respectively54 and -111 EV, so the binding between O-Cote2 and Lipss is stronger.
origin of phase engineering cote2 alloy toward kinetics-reinforced and dendrite-free lithium-sulfur batteries. adv. mater.,, doi: ht-tps: