Challenges and promises of lithium metal anode by soluble polysulfides in practical lithium–sulfur batteries

Rational Design of Sulfur-Doped Three-Dimensional Ti3C2Tx MXene/ZnS Heterostructure as Multifunctional Protective Layer for Dendrite-Free Zinc-Ion Batteries

“…As displayed in Figure f, during cycles, all profiles show a similar appearance. A general mechanism includes capacitive and diffusion contributions. − The ratio of two mechanism is estimated by the following equations: ,, where i is the current, a is a coefficient, v is the scanning rate, b = 1 shows a capacitive contribution entirely, b = 0.5 displays a diffusion contribution process completely, and a b value between 0.5 and 1 displays mixed mechanism of diffusion and capacitive contributions. As illustrated in Figure g,h, b values are about 0.69 (peak 1), 0.51 (peak 2), 0.66 (peak 3), and 0.58 (peak 4), respectively, indicating a blended mechanism of capacitance and diffusion behaviors. The ratio of capacitive and diffusion contributions is obtained by calculating k 1 and k 2 values.…”

Fabrication of a Covalent Triazine Framework Functional Interlayer for High-Performance Lithium–Sulfur Batteries

“…The disappearance of the peak representing the stretch of NH2 in the structure demonstrated the complete conversion of this reaction [39]. The characteristic peaks in the 13 C NMR spectrum reflect the carbon chemical environment at different positions (Figure 2d). The signal at 185.1 ppm can be ascribed to the ketone carbonyl C=O while the peaks at ~147.3 and 109.1 ppm are attributed to C-N and C=C, respectively.…”

“…The simulated interlayer distance is ~3.6 Å, which is very close to the value calculated from the XRD pattern. The functional group and chemical position of the CTF were confirmed by FT-IR, 13 C NMR, and XPS spectra. In the FT-IR spectrum, the peaks at 1628, 1517, and 1253 cm −1 correspond to the stretching characteristic absorption peaks of C=O, C=C, and C-N, respectively, indicating the formation of carbonyl and triazine units in the CTF skeleton (Figure 2c).…”

“…During the charge-discharge cycles, the polysulfide intermediates will shuttle across the separator and react with the lithium anode, resulting in rapid capacity loss and low Coulombic efficiency of the sulfur cathode [2][3][4][5][6]. To reduce the shuttling effect of polysulfides, tremendous efforts have been devoted to developing nanostructured sulfur hosts, such as carbon-based materials, conductive polymers, transition metal oxides, and their composites [7][8][9][10][11][12][13]. These sulfur-host materials can enhance the polysulfide retention by physically confining the polysulfide intermediates in the pores.…”

Stabilizing Li Plating by a Fluorinated Hybrid Protective Layer

“…X-ray photoelectron spectroscopy (XPS) can detect the composition change at the interface of MgF 2 @Li, which is used to prove the occurrence of surface reactions. − The Li 1s (Figure d) and Mg 1s (Figure e) peaks at 54.4 and 1303.2 eV correspond to the presence of Li 3 Mg 7 . Li 1s peak and F 1s peak at 55.4 eV (Figure d) and 685.7 eV (Figure f) can once again prove the formation of the product LiF.…”