Wu Xianyong, Markir Aaron, Ma Lu, Xu Yunkai, Jiang Heng, Leonard Daniel P, Shin Woochul, Wu Tianpin, Lu Jun, Ji Xiulei
Department of Chemistry, Oregon State University, Corvallis, Oregon, 97331-4003, USA.
X-ray Science Division, Advanced Photon Sources, Argonne National Laboratory, Lemont, Illinois, 60439, USA.
Angew Chem Int Ed Engl. 2019 Sep 2;58(36):12640-12645. doi: 10.1002/anie.201905875. Epub 2019 Jul 30.
The elemental sulfur electrode with Cu as the charge carrier gives a four-electron sulfur electrode reaction through the sequential conversion of S↔CuS↔Cu S. The Cu-S redox-ion electrode delivers a high specific capacity of 3044 mAh g based on the sulfur mass or 609 mAh g based on the mass of Cu S, the completely discharged product, and displays an unprecedently high potential of sulfur/metal sulfide reduction at 0.5 V vs. SHE. The Cu-S electrode also exhibits an extremely low extent of polarization of 0.05 V and an outstanding cycle number of 1200 cycles retaining 72 % of the initial capacity at 12.5 A g . The remarkable utility of this Cu-S cathode is further demonstrated in a hybrid cell that employs an Zn metal anode and an anion-exchange membrane as the separator, which yields an average cell discharge voltage of 1.15 V, the half-cell specific energy of 547 Wh kg based on the mass of the Cu S/carbon composite cathode, and stable cycling over 110 cycles.
以铜作为电荷载体的元素硫电极，通过S↔CuS↔Cu₂S的顺序转化实现四电子硫电极反应。基于硫的质量，Cu-S氧化还原离子电极的比容量高达3044 mAh g，基于完全放电产物Cu₂S的质量则为609 mAh g，并且在相对于标准氢电极（SHE）为0.5 V时，展现出前所未有的高硫/金属硫化物还原电位。Cu-S电极还表现出极低的0.05 V极化程度以及出色的循环次数，在12.5 A g⁻¹的电流密度下循环1200次后仍保持初始容量的72%。这种Cu-S正极的显著实用性在采用锌金属阳极和阴离子交换膜作为隔膜的混合电池中得到进一步证明，该混合电池的平均电池放电电压为1.15 V，基于Cu₂S/碳复合正极的质量，半电池比能量为547 Wh kg⁻¹，并且能在110次循环中保持稳定。
