MnS nanoparticles embedded in N,S co-doped carbon nanosheets for superior lithium ion storage

Sulfur-Bridged Bonds Boost the Conversion Reaction of the Flexible Self-Supporting MnS@MXene@CNF Anode for High-Rate and Long-Life Lithium-Ion Batteries

“…Obviously, the well-designed 3D cross-linked network modified by MXene shows excellent specific capacity and superior rate performance. 2,7,18,30,34,35 With comparison, we can find that the flexible MMC electrode has a better electrochemical stability and a higher discharge specific capacity under the condition of the same current density. The cycling performance of the two electrode materials under a low current density of 200 mA/g for 250 cycles is shown in Figure 4c.…”

“…The peak at about 168.3 eV can be used as an indicator of the oxidized sulfur species (−SO x ), which indicates the existence of the oxygen element in the MMC electrode. 30 The C 1s high-resolution XPS spectrum (Figure 3e) can be uncoupled into three peaks located at 288.8, 285.6, and 284.8 eV, which are assigned to CO, C−S, and C−C chemical bonds, respectively. 31,32 Compared with the MC electrode, MMC shows a slight red shift of its C 1s spectrum, which is caused by the transfer of electron density from the Mn to C sites through the heterostructure interface, further confirming the promotion of electron transfer by the MnS/MXene interface.…”

Flower-like Mn/Co Glycerolate-Derived α-MnS/Co9S8/Carbon Heterostructures for High-Performance Lithium-Ion Batteries

“…For Co 2p XPS spectra (Figure a), two main peaks at 793.2 and 778.3 eV are correspondingly indexed to the Co 2p 1/2 and Co 2p 3/2 , , accompanied by two satellite peaks at around 796.2 and 781.5 eV, which indicates the valence state of Co 2+ . In Figure b, the peaks at 652.7 and 641.1 eV are typically assigned to the Mn 2p 1/2 and Mn 2p 3/2 with two satellite peaks at 657.6 and 645.4 eV, respectively, indicating the oxidation state of Mn 2+ . , Figure c shows the S 2p XPS spectrum which can be decomposed as four peaks, representing three types of sulfur species. These two characteristic peaks at 162.1 and 160.9 eV are correspondingly ascribed to the S 2p 1/2 and S 2p 3/2 , while the others at 163.6 and 162.5 eV are corresponding to satellite peak and C–S bonding, revealing that sulfur is doped into the carbon structure during the CVD process. ,, By virtue of the Gaussian fitting method, the C 1s original curve is deconvoluted into three sub-peaks placed at 285.5, 284.7, and 284.4 eV (Figure d), each belonging to C–S–C, C–C, and CC bonds. ,− The existence of C–S–C bonding is consistent with the analysis of the S 2p peak, further proving S-doping in the carbon structure.…”

“…36 In Figure 4b, the peaks at 652.7 and 641.1 eV are typically assigned to the Mn 2p 1/2 and Mn 2p 3/2 with two satellite peaks at 657.6 and 645.4 eV, respectively, indicating the oxidation state of Mn 2+ . 22,37 Figure 4c shows the S 2p XPS spectrum which can be decomposed as four peaks, representing three types of sulfur species. These two characteristic peaks at 162.1 and 160.9 eV are correspondingly ascribed to the S 2p 1/2 and S 2p 3/2 , 38 while the others at 163.6 and 162.5 eV are corresponding to satellite peak and C−S bonding, revealing that sulfur is doped into the carbon structure during the CVD process.…”

“…Apparently, all the CV graphs show similar profiles (Figure a), in which three reduction peaks (peaks 1–3) and three oxidation peaks (peaks 4–6) can be well observed, and the peak current ( i ) increases with the scan rate ( v ) increasing, suggesting the presence of the pseudocapacitive behavior. Note that i and v follow the power relation of log­( i ) = b log­( v ) + log­( a ), in which the b value reflects the corresponding electrochemical mechanisms and is determined by the slope through fitting the log­( i )–log­( v ) plot. When b is near to 0.5, it represents the diffusion-controlled behavior, when b is approaching 1.0, it represents the pseudocapacitive behavior.…”