Abstract
Nickel sulfides are regarded as one of the promising anode materials for sodium-ion batteries (SIBs), but the sluggish electrodes kinetics and rapid capacity decay, caused by their intrinsic low electrical conductivity and high bulk expansion, greatly limit their practical application. To overcome these obstacles, nano-sized, selenium-doped, nickel sulfide particles, anchored on nitrogen-doped reduced graphene oxide composites (NiS1−xSex@N–rGO), are rationally synthesized. The broad Na+ diffusion channels, resulting from Se doping, as well as the short Na+ transferring path, attributed from nano-size scale of NiS1−xSex particles, endow NiS1−xSex@N–rGO composites with ultrafast storage kinetics. Moreover, strong coupled effect between the NiS1−xSex and N–rGO is beneficial to the uniform dispersion of NiS1−xSex nanoparticles, improving electrical conductivity and suppressing the volume variation in charge/discharge process. Furthermore, the cut-off discharge voltage is modulated to realize the smaller volume change during cycle process. As a result, the fabricated anode of SIBs based on NiS1−xSex@N–rGO composites exhibits a high specific capacity of 300 mAh g−1, at the current density of 1 A g−1, after 1000 cycles with almost no capacity degradation.
Highlights
Lithium-ion batteries (LIBs) have been extensively applied in all aspects of our lives, but the limited lithium resources cannot satisfy the ever-growing demand for future electrical storage system (EES) devices [1–6]
It is noticed that 2-Methylimidazole (2-MeIm) was served as the nitrogen source and can facilitate the generation of sheet-like Ni(OH)2 [38]
The TEM images further demonstrated the homogeneous distribution of NiS1−xSex nanoparticles with diameters of 50–100 nm on N–rGO nanosheet (Figure 2c)
Summary
Lithium-ion batteries (LIBs) have been extensively applied in all aspects of our lives, but the limited lithium resources cannot satisfy the ever-growing demand for future electrical storage system (EES) devices [1–6]. Sodium-ion batteries (SIBs) are deemed to be a highly promising alternative, due to the abundant resources, low-cost and, especially, similar working mechanism to LIBs [7–9]. It is imperative to develop appropriate anode materials for SIBs. In the past years, a variety of anode materials, including hexagonal boron nitride (h–BN) [13], carbonaceous materials [14,15], alloy-based materials [16,17], transition metal oxides [18–20], and transition metal chalcogenides [21–23], have been explored as anode materials for SIBs. Among them, transition metal chalcogenides, especially nickel sulfides, have received much attention, due to their high specific capacity, rich resources, low-cost, and being environmentally benign [24–27]. The nickel sulfides suffer from a poor electrical conductivity and large volume expansion during charge/discharge process, leading to unsatisfactory specific capacity and fast capacity fading [9,28,29]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
