NiCo₂S₄ Nanosheets Grown on 3D Networks of Nitrogen‐Doped Graphene/Carbon Nanotubes: Advanced Anode Materials for Lithium‐Ion Batteries

Abstract

To meet the requirements of high‐performance lithium‐ion batteries (LIBs), a new class of electrode materials with favorable nanostructures is highly desirable. Recently, metal sulfides have been intensively studied as promising anode materials for LIBs because of their high lithium storage capacity. Among them, ternary metal sulfides can provide much higher electrochemical activity and energy storage performance than binary metal sulfides or their oxide counterparts, which makes them outstanding candidates as anode materials for next‐generation LIBs. In this work, hierarchical nanostructured hybrids of NiCo2S4 nanosheets uniformly grown on nitrogen‐doped graphene/carbon nanotube networks (NiCo2S4/NGC) have been easily prepared as novel anode materials for LIBs. Benefiting from the synergistic effects between NiCo2S4 nanosheets and conductive NGC networks, the optimized NiCo2S4/NGC hybrid exhibits greatly enhanced electrochemical performance with high initial charge capacity of 1225.4 mA h g−1 at a current density of 0.2 A g−1 and excellent cycling stability with 89 % capacity retention after 100 cycles. Moreover, its capacity can be retained at 574.8 mA h g−1 after 100 cycles even at a current density of 5 A g−1, demonstrating its exceptionally high rate performance.

Cobalt nickel nitride coated by a thin carbon layer anchoring on nitrogen-doped carbon nanotube anodes for high-performance lithium-ion batteries

“…The NiCo 2 N@C-NCNT nanocomposite electrode showed a capacity fading rate of only 0.089% per cycle at a high current density, which is even smaller than those of previously reported nanostructured NiCo 2 O 4 , NiCo 2 S 4 electrode materials or other electrode materials. 8,[35][36][37][38][39] For comparison, NiCo 2 O 4 -CNT nanocomposite as anodes were also evaluated at a high current density of 2000 mA g À1 , as shown in Fig. 4e.…”

Mixed Metal Sulfides for Electrochemical Energy Storage and Conversion

“…[33,61,[107][108][109][110] The carbonaceous materials can effectively prevent the agglomeration of nanoscale MMSs, promote electron transport, increase the electroactive sites, and enhance the stability of MMSs.…”

“…[109,124,216] The carbon materials can also increase the conductivity of the nanocomposite, resulting in high rate performance and prevent the self-aggregation of NiCo 2 S 4 nanomaterials for better utilization. Zhang et al synthesized a 3D hierarchical nanocomposite composed of ultrathin NiCo 2 S 4 nanosheets and N-doped graphene/CNT (NGC).…”

“…Zhang et al synthesized a 3D hierarchical nanocomposite composed of ultrathin NiCo 2 S 4 nanosheets and N-doped graphene/CNT (NGC). [109] The NiCo 2 S 4 nanosheets are grown on the NGC matrix through a one-pot solvothermal route. Figure 5a,b shows that the NiCo 2 S 4 nanosheets are uniformly distributed and confined within the porous NGC networks, showing a high specific surface area of 168.6 m 2 g −1 .…”

NiCo2S4-Based Materials for Electrochemical Applications

“…At about the same time, Jin et al [13] fabricated hierarchical NiCo2S4 hollow spheres, of which possessed a specific capacity of 696 mA•h•g −1 for 100 cycles (0.2 A•g -1 ). Liu et al [26] prepared hierarchical nanostructured hybrids composed by NiCo2S4 nanosheets and nitrogen-doped graphene/carbon nanotube networks, and the composite material displayed high initial charge capacity of 1225.4 mA•h•g −1 (0.2 A•g -1 ). Recently, Xu et al [27] reported NiCo2S4/Ni0.96S nanoparticles anchored in 3D grapheme aerogel, and the material has a superlong cycling stability of 620 mAh•g -1 for 800 cycles (1 A•g -1 ).…”