Stable freestanding Li-ion battery cathodes by in situ conformal coating of conducting polypyrrole on NiS-carbon nanofiber films

Silica Restricting the Sulfur Volatilization of Nickel Sulfide for High‐Performance Lithium‐Ion Batteries

“…[13][14][15] Due to its abundance and low prices, mineral-type nickel sulfide has gained much attention in photo-electrochemistry and is widely used in semiconductor, magnetic, photo-electrocatalytic, thermoelectric, phase-converting materials, and electrode materials for rechargeable lithium-ion batteries. [23,24] However, despite extensive research efforts, improving the performance of nickel sulfide to achieve high specific capacity and long cycle life is still a challenge. [20] However, nickel sulfides are seldom regarded as excellent candidates for lithium-ion batteries, mainly due to the instability in the nickel-rich active material.…”

Silica‐Mediated Formation of Nickel Sulfide Nanosheets on CNT Films for Versatile Energy Storage

“…Thus, the search for suitable electrodes with both high mechanical flexibility and excellent electrochemical performance has become a new research hotspot. Various carbon nanomaterials, especially carbon nanotubes (CNTs), have been regarded as feasible for this task, and they can be easily assembled into different bulky forms, including fibers, films, foams, and gels . To further enhance their electrochemical performance, various active species have been incorporated with them in the construction of composite electrodes, including sulfides, carbides, oxides, and other metal/nonmetal compounds .…”

“…Among them, metal sulfides, especially nickel sulfides, have the unique advantages of large interlayer distance, versatile surface chemistry, multiple crystal structures, and high redox reversibility, giving them excellent potential for a wide range of electrochemical applications . In addition, the nickel sulfides in 2D nanosheet form provide the extra merits of shortened distances for ion migration, better exposed active surfaces for electrochemical processes, and enhanced mechanical flexibility in comparison with their bulk counterparts . Consequently, these multiple advantages have made them especially suitable for energy storage via surface redox reactions (e.g., electrochemical capacitors), reversible intercalation/deintercalation of ions (e.g., lithium/sodium ion batteries), and reversible electrochemical conversions (i.e., lithium/sodium–sulfur batteries).…”

Advanced Matrixes for Binder‐Free Nanostructured Electrodes in Lithium‐Ion Batteries

“…Until now, various promising cathode materials, such as vanadium pentoxide (V 2 O 5 ), [ 202 ] Li 3 V 2 (PO 4 ) 3 nanocrystals, [ 203–205 ] LiNi 0.5 Mn 1.5 O 4 NPs, [ 206 ] NiS/polypyrrole composite, [ 207 ] Li 2 Mn 0.8 Fe 0.2 SiO 4 , [ 208 ] and LiFePO 4 , [ 209,210 ] have been directly grown on the surface of CNFs or encapsulated inside the CNFs. Among these active cathode materials, olivine LiFePO 4 has attracted wide attention due to its impressive cycling stability, high discharge potential, excellent thermal stability and safety.…”