Ni/Li antisite induced disordered passivation layer for high-Ni layered oxide cathode material

Multi-heteroatom-Doped Carbon Matrix and N-Doped Carbon Shell Double Protection Enabled Superb Stability of Nickel Diselenide for Lithium Storage

“…It can be seen from the full spectrum that C, N, O, P, Ni, and Se are presented in the samples (Figure S1), indicating the successful doping of multi-heteroatoms in the NiSe 2 @NC/rGO composite. The C 1s detailed scan shows three obvious binding energies at 284.8, 286.2, and 289.0 eV, which can be attributed to CC, C–O, and O–CO, respectively (Figure a). , This agrees well with the high-resolution spectrum of O 1s, where three binding energies of 531, 532, and 533.5 eV can be observed and ascribed to OC, P–O–C, and C–O, respectively (Figure b). − In the detailed scan of N 1s, two peaks at 398.3 and 400.0 eV corresponding to the characteristic peaks of pyridine N and graphite N, respectively, are clearly shown in Figure c. , In Figure d, there are two characteristic peaks with binding energies of 137.7 and 133.6 eV, indicating the existence of two forms of P atoms (PO and P–O). − Moreover, in the detailed scan of Ni 2p, there are two characteristic peaks at 873.6 and 856 eV together with satellite peaks at 879.5 and 861.6 eV, respectively, indicating the presence of Ni 2+ in NiSe 2 @NC/rGO composite (Figure e). ,, In Figure f, the binding energies of Se 3d 5/2 and Se 3d 3/2 are observed at 54.2 and 55.9 eV; in addition, the characteristic peaks at 59.4 eV are mainly attributed to Se–O/Se–C. − This result further solidified the formation of NiSe 2 as well as the successful doping of multi-heteroatom in NiSe 2 @NC/rGO composite.…”

“…40−42 Moreover, in the detailed scan of Ni 2p, there are two characteristic peaks at 873.6 and 856 eV together with satellite peaks at 879.5 and 861.6 eV, respectively, indicating the presence of Ni 2+ in NiSe 2 @NC/rGO composite (Figure 2e). 11,43,44 In Figure 2f, the binding energies of Se 3d 5/2 and Se 3d 3/2 are observed at 54.2 and 55.9 eV; in addition, the characteristic peaks at 59.4 eV are mainly attributed to Se−O/Se−C. 45−47 This result further solidified the formation of NiSe 2 as well as the successful doping of multi-heteroatom in NiSe 2 @NC/rGO composite.…”

“…First, a Ni-MOF/GO composite was obtained by a solvothermal reaction using nickel nitrate and a cyclo-triphosphazene-based linker as reported in our previous work (Figure a). , Further selenization of the Ni-MOF/GO composite provides the multi-heteroatom-doped carbonaceous NiSe 2 /C/rGO composite. A further in situ polydopamine cladding process of NiSe 2 /C/rGO composite followed by a carbonization step provided the N-doped carbon shell encapsulated product NiSe 2 @NC/rGO.…”

“…Researchers have made tremendous efforts to improve the electrochemical performance of LIBs to meet the growing demands for high-performance energy storage devices. In particular, it is believed that the preparation of the next-generation electrode materials is the most practical and feasible strategy to pursue high-energy-density LIBs. − Transition metal selenides (TMSs) have drawn much attention due to their high theoretical specific capacity as electrodes for LIBs. Among those, nickel diselenides (NiSe 2 ) are regarded as one of the utmost potential electrode materials for secondary batteries due to their rich oxidation states and relatively low resistivity.…”

Structural Stabilization of Cation-Disordered Rock-Salt Cathode Materials: Coupling between a High-Ratio Inactive Ti4+ Cation and a Mn2+/Mn4+ Two-Electron Redox Pair

“…Due to the oxygen release triggered by the anion redox reaction, thermal stability is extremely important for cation-disordered cathode materials, especially when they are at a fully charged state. ,,− Figure j compares the DSC curves of the two fully charged cathodes. The exothermic peak temperature of LTMO3 is at 246.4 °C, with the total heat flow of 1530.4 J g –1 , while for LTMO2, the peak temperature is increased to 258.2 °C and the heat flow significantly decreases to 823.0 J g –1 .…”