Fig. 2: Lithium electrochemical tuning method and structural characterizations.
From: Double sulfur vacancies by lithium tuning enhance CO2 electroreduction to n-propanol
a Schematic diagram of lithium-ion battery assembled with CuS (cathode) and Li metal (anode). b Discharge capacity of CuS (blue dots) and the atomic ratio of S/Cu (red stars) with respect to the cycle number at a constant current of 0.044 mA·cm-2 in the voltage range of 0.01–3 V. Sulfur atoms in the CuS lattice were controllably taken away to form Li2S, resulting in CuSx-DSV. c Spherical aberration corrected HRTEM, d HAADF-STEM image, and e corresponding intensity profiles extracted from the blue line of CuSx-DSV in d. The typical lattice arrangement of hexagonal phase CuS was presented by the higher contrast of Cu and the lower contrast of sulfur atoms. The intensity of lower left sulfur atoms was around 20 units, almost half of S atoms (~ 40 unit), suggesting the absence of single sulfur atoms. The pink, yellow spheres, and yellow dashed circles indicate copper, sulfur atoms, and sulfur vacancies, respectively. f ESR spectra of CuS (blue curve) and CuSx-DSV (red curve).
