Adaptively Reforming Natural Enzyme to Activate Catalytic Microenvironment for Polysulfide Conversion in Lithium-Sulfur Batteries

作者：Liang, Ce; Liu, Jun; Yu, Shuang; Li, Tingting; Wang, Haohao; Liu, Yahui; Yang, Shuo^*; Cai, du. cn Dong^*; Nie, Huagui^*; Yang, Zhi^*

来源：ACS applied materials & interfaces, 2023, 15(1): 1256-1264.

DOI：10.1021/acsami.2c18976

• lithium-sulfur battery
• polysulfide conversion
• hemocyanin
• denaturation
• catalytic microenvironment

Catalyzing polysulfide conversion is a promising way toward accelerating complex and sluggish sulfur redox reactions (SRRs) in lithium-sulfur batteries. Reasonable alteration of an enzyme provides a new means to expand the natural enzyme universe to catalytic reactions in abiotic systems. Herein, we design and fabricate a denatured hemocyanin (DHc) to efficiently catalyze the SRR. After denaturation, the unfolded beta-sheet architectures with exposed rich atomically dispersed Cu, O, and N sites and intermolecular H-bonds are formed in DHc, which not only provides the polysulfides for a strong spatial confinement effect in microenvironment via S-O and Li center dot center dot center dot N interactions but also activates chemical channels for electron/Li+ transport into the Cu active center via H/Li-bonds to catalyze polysulfide conversion. As expected, the charge/discharge kinetics of DHc-containing cathodes is fundamentally improved in cyclability with nearly 100% Coulombic efficiency and capacity even under high sulfur loading (4.3 mg cm-2) and lean-electrolyte (8 mu L mg-1) conditions.