Trapping and catalytic conversion of polysulfides by kirkendall effect built hollow NiCo 2 S 4 nano-prisms for advanced

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Trapping and catalytic conversion of polysulfides by kirkendall effect built hollow NiCo2S4 nano-prisms for advanced sulfur cathodes in Li–S battery Huaiyue Zhang1, Guanxi Liu1, Jing Li1, Hongtao Cui1, Yuanyuan Liu1, and Meiri Wang1,*

1

Shandong Collaborative Innovation Center of Light Hydrocarbon Transformation and Utilization, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China

Received: 23 August 2020

ABSTRACT

Accepted: 26 October 2020

To address the problems of low active utilization and fast capacity decay in practical application of lithium–sulfur (Li–S) battery, an effective and widely used strategy is incorporating polar materials into sulfur cathode to tune the redox reaction of polysulfides in recent years. Herein, a hollow nano-prism structured bimetallic sulfide (NiCo2S4) built by kirkendall effect is proposed to trap and catalyze conversion of polysulfides. Beneficial from the strong interaction and super electrocatalytic effect for the intermediates of sulfur reduction, the NiCo2S4 incorporated in sulfur cathode can significantly ease the shuttle effect, decrease the activation energy and dynamically accelerates the transformation of the polysulfides. As expected, together with the high conductivity, hollow structure and compositional superiorities, the sulfur cathode with NiCo2S4 for Li–S battery exhibits apparently enhanced sulfur utilization and improved cycling performance that preserves super low capacity fading rate of 0.05% per cycle after 800 cycles at 1 C. This work has guiding significance in the design of a sulfur cathode for advanced Li–S battery.

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Springer Science?Business

Media, LLC, part of Springer Nature 2020

Handling Editor: Kyle Brinkman.

Address correspondence to E-mail: [email protected]

https://doi.org/10.1007/s10853-020-05511-8

J Mater Sci

GRAPHICAL ABSTRACT

Low dissolution

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Li2S6

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Li2S4

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Li2S Li2S2

NiCo2S4

Carbon

Introduction Lithium–sulfur (Li–S) battery with high theoretical specific capacity (1672 mAh g-1) and high specific energy density (2600 Wh Kg-1) has been considered as one promising next-generation energy storage device [1–4]. However, the practical application of Li–S battery is significantly hindered by the intrinsic properties of the electrode materials, such as the poor conductivity of sulfur (5 9 10-30 S cm-1), the dissolution and diffusion of lithium polysulfides (Li2SX, 4 B X B 8) and the poor electrochemical conversion kinetics of polysulfides in the electrolyte, which result in low utilization efficiency of sulfur and short cycling life [5, 6]. In order to solve these problems regarded to the cathode materials, various strategies have been developed during the past few years. Among them, to anchor the sulfur in carbonaceous materials is a most common and effective strategy due to their excellent electrical conductivity and abundant pore volume [6–8]. However, the week physical affinity between carbon and polysulfides makes it tend to lose initial electrical contact with carbonaceous matrix, ca