Tubular CoFeP@CN as a Mott-Schottky catalyst with multiple adsorption sites for robust lithium-sulfur batteries

The shuttle effect and the sluggish reaction kinetics of lithium polysulfide (LiPS) seriously compromise the performance of lithium-sulfur batteries (LSBs). To overcome these limitations and enable the fabrication of robust LSBs, here the use of a Mott-Schottky catalyst based on bimetallic phosphide...

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Bibliographic Details
Authors: Zhang, Chaoqi|||0000-0002-0357-235X, Du, Ruifeng, Jacas Biendicho, Jordi|||0000-0001-5981-6168, Yi, Mingjie, Xiao, Ke, Yang, Dawei|||0000-0002-3842-8286, Zhang, Ting|||0000-0002-0317-9662, Wang, Xiang, Arbiol i Cobos, Jordi|||0000-0002-0695-1726, Llorca, Jordi|||0000-0002-7447-9582, Zhou, Yingtang|||0000-0002-8678-295X, Morante, Joan Ramon|||0000-0002-4981-4633, Cabot i Codina, Andreu|||0000-0002-7533-3251
Format: article
Publication Date:2021
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:271937
Online Access:https://ddd.uab.cat/record/271937
https://dx.doi.org/urn:doi:10.1002/aenm.202100432
Access Level:Open access
Keyword:Carbon nitrides
Lithium-sulfur batteries
Metal phosphides
Mott-Schottky heterostructure
Polysulfides
Shuttle effect
Description
Summary:The shuttle effect and the sluggish reaction kinetics of lithium polysulfide (LiPS) seriously compromise the performance of lithium-sulfur batteries (LSBs). To overcome these limitations and enable the fabrication of robust LSBs, here the use of a Mott-Schottky catalyst based on bimetallic phosphide CoFeP nanocrystals supported on carbon nitride tubular nanostructures as sulfur hosts is proposed. Theoretical calculations and experimental data confirm that CoFeP@CN composites are characterized by a suitable electronic structure and charge rearrangement that allows them to act as a Mott-Schottky catalyst to accelerate LiPS conversion. In addition, the tubular geometry of CoFeP@CN composites facilitates the diffusion of Li ions, accommodates volume change during the reaction, and offers abundant lithiophilic/sulfiphilic sites to effectively trap soluble LiPS. Therefore, S@CoFeP@CN electrodes deliver a superior rate performance of 630 mAh g at 5 C, and remarkable cycling stability with 90.44% capacity retention over 700 cycles. Coin cells with high sulfur loading, 4.1 mg cm, and pouch cells with 0.1 Ah capacities are further produced to validate their superior cycling stability. In addition, it is demonstrated here that CoFeP@CN hosts greatly alleviate the often overlooked issues of low energy efficiency and serious self-discharging in LSBs.

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