A composite of CoNiP quantum dot-decorated reduced graphene oxide as a sulfur host for Li–S batteries

Abstract

The “shuttle effect” and sluggish reaction kinetics of lithium polysulfides lead to inferior cycling performance and rate capability of Li-S batteries, which hurdles their practical application. Herein, a composite of...

Construction of Ni/Ni3N heterojunctions as reversible micro-reaction centers for lithium polysulfides

“…Furthermore, the cleavage of the Ni–N bond could result in a sharp increase of Ni ions which can serve as Lewis-acid sites to anchor soluble LiPSs. 14,26,29,30 The above XPS results testify that there is intense chemisorption between the Ni/Ni 3 N and LiPSs. Due to the strong electronic interaction at the heterojunction interface, the “shuttle effect” can be effectively alleviated.…”

“…On lowering the nitridation temperature, the sample will be completely converted to Ni 3 N, while on increasing the nitridation temperature, the sample will be completely converted to Ni (Experimental section †). 14,15 The morphology, structural characteristics, and components of the prepared CNT, Ni 3 N-CNT, and Ni/Ni 3 N-CNT were investigated by SEM and TEM. As shown in Fig.…”

“…Due to the strong electronic interaction at the heterojunction interface, the "shuttle effect" can be effectively alleviated. 14,30 Since the ability of the hosts to adsorb LiPSs plays an important role in the charge-discharge process of the sulfur cathodes, the adsorption energies of 31 To investigate the kinetic behavior and Li + diffusion characteristic in the Ni/Ni 3 N-CNT/S electrode, CV tests at various scan rates (Fig. 5b and c) and EIS analysis (Fig.…”

“…The DE of the Ni/Ni 3 N-CNT/S electrode (182.9 mV) is lower than that of the Ni 3 N-CNT/S (200.2 mV) and CNT/S (225.6 mV) electrodes, suggesting that the Ni/Ni 3 N heterojunctions can accelerate the reaction kinetics. 14,30,37,38 The nucleation kinetics of Li 2 S can be reected using the voltage dip at the nucleation site of Li 14,30,37,38 To gain insight into the role of Ni/Ni 3 N heterojunctions in enhancing the electrochemical reaction kinetics, the entire conversion process of LiPSs was considered. As shown in Fig.…”

“…On lowering the nitridation temperature, the sample will be completely converted to Ni 3 N, while on increasing the nitridation temperature, the sample will be completely converted to Ni (Experimental section†). 14,15…”