Advancing Li-ion storage performance with hybrid vertical carbon/Ni_(3)S_(2)-based electrodes

Conversion-reaction induced charge storage mechanisms of transition metal sulphides have received considerable interest in designing high-capacity electrodes for electrochemical energy storage devices.However,their low conductivity and structural degradation during cycling limit their applications as energy storage devices.A combination of different nickel sulphide phases tailored with carbon nanostructures is suggested to address these limitations.Herein,a facile,two-step approach is demonstrated for fabricating a hybrid electrode,consisting of trinickel disulphide(Ni_(3)S_(2))formed on a metallic Ni nanoparticle supported by vertical carbon nanotubes(VCN)backbone in the form Ni_(3)S_(2)/Ni@VCN.Ni_(3)S_(2)/Ni@VCN electrodes were tested as anode for lithium-ion batteries,and the electrode featured outstanding lithiumstorage capabilities with a high reversible capacity(1113 m Ah g^(-1) after 100 cycles at 100 m A g^(-1)),excellent long-term cycling stability(770 m Ah g^(-1) after 500 cycles at 200 m A g^(-1)),and good rate capability.The resulting electrode performance is one of the best Li-ion storage capabilities in the Ni_(3)S_(2)-type anode materials described.A unique “broccoli-like”structure of polycrystalline Ni_(3)S_(2)capped on conductive VCN backbone helps the interface storage process and boosts lithium storage performance.

N-Graphene Nanowalls via Plasma Nitrogen Incorporation and Substitution: The Experimental Evidence

Incorporating nitrogen(N)atom in graphene is considered a key technique for tuning its electrical properties.However,this is still a great challenge,and it is unclear how to build N-graphene with desired nitrogen configurations.There is a lack of experimental evidence to explain the influence and mechanism of structural defects for nitrogen incorporation into graphene compared to the derived DFT theories.Herein,this gap is bridged through a systematic study of different nitrogen-containing gaseous plasma post-treatments on graphene nanowalls(CNWs)to produce N-CNWs with incorporated and substituted nitrogen.The structural and morphological analyses describe a remarkable difference in the plasma–surface interaction,nitrogen concentration and nitrogen incorporation mechanism in CNWs by using different nitrogen-containing plasma.Electrical conductivity measurements revealed that the conductivity of the N-graphene is strongly influenced by the position and concentration of C–N bonding configurations.These findings open up a new pathway for the synthesis of N-graphene using plasma post-treatment to control the concentration and configuration of incorporated nitrogen for application-specific properties.