Synthesis of NiS/carbon composites as anodes for high-performance sodium-ion batteries

Chemical vapor deposition growth of carbon nanotube confined nickel sulfides from porous electrospun carbon nanofibers and their superior lithium storage properties

“…The D-band reects the defects in carbon-based materials associated with vacancies and amorphous carbon species, while the G peak originating from the stretching motion of the sp 2 carbon pairs corresponds to the ordered graphitic carbon species. 13,18 The intensity ratio of the D-band to the G-band (I D /I G ) is 1.079, indicating a high defect degree of the hybrid material, which is benecial for Liion storage in the graphene-based anodes. 13 The increase in the disorder may be attributed to the inuence of the embedded Ni 3 S 2 nanoparticles and the defects introduced by N-doping and S-doping.…”

“…13,18 The intensity ratio of the D-band to the G-band (I D /I G ) is 1.079, indicating a high defect degree of the hybrid material, which is benecial for Liion storage in the graphene-based anodes. 13 The increase in the disorder may be attributed to the inuence of the embedded Ni 3 S 2 nanoparticles and the defects introduced by N-doping and S-doping. 18,32 Besides, no apparent peaks for Ni 3 S 2 can be observed, which may be attributed to its full incorporation into the graphite matrix.…”

“…4b), three deconvoluted peaks located at 401, 400.1 and 398.3 eV can be assigned to the graphitic, pyrrolic and pyridinic types of N atoms. 13,17,33 It's noteworthy that the existence of pyridinic N can increase electron conduction, thus facilitating the improvement of the rate performance of the electrodes. In addition, the N heteroatoms can help to enhance the whole architectural stability and induce more defects, disorder and a lower degree of crystallinity, which can create more Li + storage sites and thus enhance capacity.…”

“…[9][10][11] In particular, the carbon-based materials with intercalation-deintercalation mechanisms exhibit minor volume changes and show excellent electrochemical performance owing to their high electronic conductivity and superior mechanical properties. 9,[12][13][14][15] In addition, doping carbonaceous materials with exotic elements such as sulfur and nitrogen can also enhance the lithium storage performance, but still with limitations. [16][17][18][19] Recently, nickel suldes (e.g., NiS, NiS 2 , Ni 3 S 2 , and Ni 9 S 8 ) have been proposed as alternative anodes in LIBs owing to their high capacities achieved via a conversion mechanism.…”

“…Thus, hybridizing nickel suldes with carbon-based nanostructures has been suggested as a potential strategy to overcome these limitations. 13,23 Herein, we demonstrate the facile synthesis of a unique hierarchical architecture containing carbon nanotubes (CNTs), carbon nanobers (CNFs) and nickel sulde (NS) nanoparticles, in which CNT conned NS particles are directly grown from porous N-doped CNFs (denoted as CNT@NS@CNFs) via a combined electrospinning and chemical vapor deposition method. When used as anode materials for LIBs, the dendritic CNT@NS@CNFs demonstrated superior cycling stability and rate capability, owing to the advantageous structural characteristics.…”