天津大学杨全红团队利用分子印迹技术实现高能锂电池的工程催化缺陷。相关研究成果发表在2024年5月31日出版的《国家科学评论》。

多相催化有望加速锂硫电池中涉及硫的转化反应。由于弱匹配的固体-固体电催化界面，固态Li₂S离解仍然是速率限制步骤。

研究人员提出了一种电化学分子印迹策略，使金属硫化物（MS）催化剂在电化学去除预注入的Li₂S的位置上具有印迹缺陷。这种特制的缺陷使催化剂能够仅与Li₂S反应物中的Li原子结合，并延长Li-S键，从而降低充电过程中的反应能垒。印迹Ni₃S₂催化剂由于在所检查的MS催化剂中缺陷浓度最高而显示出最佳活性。

对于没有印迹空位的对应物，Li₂S氧化电位从2.96V显著降低到2.34V，并且实现了具有优异循环性能的Ah级袋状电池。在贫电解质/硫比为1.80μL mgS^–1的情况下，该电池实现了超过500 Wh kg^–1的高能量密度。

据了解，多相催化有望加速锂硫电池中涉及硫的转化反应。由于弱匹配的固-固电催化界面，固态Li2S解离仍然是限速步骤。

附：英文原文

Title: Engineering catalytic defects via molecular imprinting for high energy Li-S pouch cells

Author: Zhao, Yufei, Geng, Chuannan, Wang, Li, Cao, Yun, Yang, Haotian, Peng, Linkai, Jiang, Xin, Guo, Yong, Ye, Xiaolin, Lv, Wei, Yang, Quan-Hong

Issue&Volume: 2024-05-31

Abstract: Heterogeneous catalysis promises to accelerate sulfur-involved conversion reactions in lithium-sulfur batteries. Solid-state Li2S dissociation remain as the rate-limiting step because of the weakly matched solid-solid electrocatalysis interfaces. We propose an electrochemically molecular-imprinting strategy to have a metal sulfide (MS) catalyst with imprinted defects in positions from which the pre-implanted Li2S has been electrochemically removed. Such tailor-made defects enable the catalyst to bind exclusively to Li atoms in Li2S reactant and elongate the Li-S bond, thus decrease the reaction energy barrier during charging. The imprinted Ni3S2 catalyst shows the best activity due to the highest defect concentration among the MS catalysts examined. The Li2S oxidation potential is substantially reduced to 2.34 V from 2.96 V for the counterpart free of imprinted vacancies, and an Ah-level pouch cell is realized with excellent cycling performance. With a lean electrolyte/sulfur ratio of 1.80 μL mgS–1, the cell achieves a benchmarkedly high energy density beyond 500 Wh kg–1.

DOI: 10.1093/nsr/nwae190

Source: https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwae190/7686132searchresult=1&login=false