Molybdenum Boride as an Efficient Catalyst for Polysulfide Redox to Enable High‐Energy‐Density Lithium–Sulfur Batteries

Journal Article · Sun Aug 30 00:00:00 EDT 2020 · Advanced Materials

DOI:https://doi.org/10.1002/adma.202004741· OSTI ID:1785848

He, Jiarui ^[1]; Bhargav, Amruth ^[1]; Manthiram, Arumugam  ^[1]

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1. Materials Science and Engineering Program &, Texas Materials Institute The University of Texas at Austin Austin TX 78712 USA

Abstract Lithium–sulfur (Li–S) batteries, despite having high theoretical specific energy, possess many practical challenges, including lithium polysulfide (LiPS) shuttling. To address the issues, here, hydrophilic molybdenum boride (MoB) nanoparticles are presented as an efficient catalytic additive for sulfur cathodes. The high conductivity and rich catalytically active sites of MoB nanoparticles allow for a fast kinetics of LiPS redox in high‐sulfur‐loading electrodes (6.1 mg cm ⁻² ). Besides, the hydrophilic properties and good wettability toward electrolyte of MoB can facilitate electrolyte penetration and LiPS redox, guaranteeing a high utilization of sulfur under a lean‐electrolyte condition. Therefore, the cells with MoB achieve impressive electrochemical performance, including a high capacity (1253 mA h g ⁻¹ ) and ultralong lifespan (1000 cycles) with a low capacity fade rate of 0.03% per cycle. Also, pouch cells fabricated with the MoB additive deliver an ultrahigh discharge capacity of 947 mA h g ⁻¹ , corresponding to a low electrolyte‐to‐capacity ratio of about 4.8 µL (mA h) ⁻¹ , and remain stable over 55 cycles under practically necessary conditions with a low electrolyte‐to‐sulfur ratio of 4.5 µL mg ⁻¹ .

• Sponsoring Organization: USDOE
• Grant/Contract Number: DE‐SC0005397
• OSTI ID: 1785848
• Journal Information: Advanced Materials, Journal Name: Advanced Materials Vol. 32 Journal Issue: 40; ISSN 0935-9648
• Publisher: Wiley Blackwell (John Wiley & Sons)
• Country of Publication: Germany
• Language: English