In Situ Anchoring Anion‐Rich and Multi‐Cavity NiS₂ Nanoparticles on NCNTs for Advanced Magnesium‐Ion Batteries

Abstract

Magnesium (Mg)‐ion batteries with low cost and good safety characteristics has attracted a great deal of attention recently. However, the high polarity and the slow diffusion of Mg2+ in the cathode material limit the development of practical Mg cathode materials. In this paper, an anion‐rich electrode material, NiS2, and its composite with Ni‐based carbon nanotubes (NiS2/NCNTs) are explored as the cathode materials for Mg‐ion batteries. These NiS2/NCNTs with excellent Mg2+ storage property is synthesized by a simple in situ growth of NiS2 nanoparticles on NCNTs. NiS2 with both a large regular cavity structure and abundant sulfur‐sulfur (SS) bonds with high electronegativity can provide a large number of active sites and unobstructed transport paths for the insertion–disinsertion of Mg2+. With the aid of 3D NCNTs skeleton as the transport channel of the electron, the NiS2/NCNTs exhibit a high capacity of 244.5 mAh g−1 at 50 mA g−1 and an outstanding rate performance (94.7 mAh g−1 at 1000 mA g−1). It achieves capacitance retention of 58% after 2000 cycles at 200 mA g−1. Through theoretical density functional theory (DFT) calculations and a series of systematic ex situ characterizations, the magnesiation/demagnesiation mechanisms of NiS2 and NiS2/NCNTs and are elucidated for fundamental understanding.

High-Performance NiS2 Hollow Nanosphere Cathodes in Magnesium-Ion Batteries Enabled by Tunable Redox Chemistry

“…The electrochemical impedance spectroscopy (EIS) results suggest that 8-NiS 2 hollow nanospheres have a lower resistance after 10 cycles than before cycling (Figure S10), explaining the increase in capacity upon cycling. As illustrated in Table S1, the electrode of 8-NiS 2 hollow nanospheres demonstrates obvious advantages in terms of capacity and cycles, indicating the successful rational design of the electrodes. ,,,− …”

“…30−32 Notable examples include NiS nanoparticles embedded in carbon nanofibers with a capacity of 265 mA h g −1 after 45 cycles at 50 mA g −1 , 33 CuSe nanoflakes with a capacity of 180 mA h g −1 after 100 cycles at 200 mA g −1 (218 mA h g −1 at 50 mA g −1 , rate capacity), 34 and NiS 2 nanoparticles in carbon nanotubes, delivering a capacity of 95.2 mA h g −1 after 2000 cycles at 200 mA g −1 (244.5 mA h g −1 at 50 mA h g −1 , rate capacity). 30 However, these nonhollow TMD nanostructures are unable to accommodate the large volumetric changes that occur during repeated magnesiation and demagnesiation, resulting in electrode pulverization and poor cycling stability. Therefore, exploring and developing promising cathodes with internal void space and high magnesium storage performance is imperative.…”

“…Various strategies have been employed to alleviate these problems, including coupling with carbon-based materials, fabricating microstructures, and introducing heteroatom doping. − Notable examples include NiS nanoparticles embedded in carbon nanofibers with a capacity of 265 mA h g –1 after 45 cycles at 50 mA g –1 , CuSe nanoflakes with a capacity of 180 mA h g –1 after 100 cycles at 200 mA g –1 (218 mA h g –1 at 50 mA g –1 , rate capacity), and NiS 2 nanoparticles in carbon nanotubes, delivering a capacity of 95.2 mA h g –1 after 2000 cycles at 200 mA g –1 (244.5 mA h g –1 at 50 mA h g –1 , rate capacity) . However, these nonhollow TMD nanostructures are unable to accommodate the large volumetric changes that occur during repeated magnesiation and demagnesiation, resulting in electrode pulverization and poor cycling stability.…”

NiS2 nanoparticles by the NaCl-assisted less-liquid reaction system for the magnesium-ion battery cathode

“…Ye et al . 26 synthesized an anion-rich electrode material NiS 2 using a solvothermal method. The material has a large cavity structure and abundant active sites, which can provide a circulation channel for Mg 2+ transport.…”

Hierarchically porous N-doped carbon nanosheets with atomically dispersed Fe/Co dual-metallic sites for efficient and robust oxygen electrocatalysis in Zn–air batteries

“…However, the concerns related to scarcity, high cost and unsatisfied stabilities of PGM catalysts preclude their large-scale commercialization. [7][8][9][10][11] In this regard, transition metal and nitrogen co-doped carbon (TM-N-C, where TM represents Fe, Co, Mn, Cu etc. ), especially Fe-N-C, are the most promising alternative to PGM catalysts by virtue of their low cost, high activity as well as robust stability.…”