Self-Catalyzed Synthesis of Length-Controlled One-Dimensional Nickel Oxide@N-Doped Porous Carbon Nanostructures from Metal Ion Modified Nitrogen Heterocycles for Efficient Lithium Storage

Abstract

Transition metal oxides with the merits of high theoretical capacities, natural abundance, low cost, and environmental benignity have been regarded as a promising anodic material for lithium ion batteries (LIBs). However, the severe volume expansion upon cycling and poor conductivity limit their cycling stability and rate capability. To address this issue, NiO embedded and N-doped porous carbon nanorods (NiO@NCNR) and nanotubes (NiO@NCNT) are synthesized by the metalcatalyzed graphitization and nitridization of monocrystalline Ni(II)-triazole coordinated framework and Ni(II)/melamine mixture, respectively, and the following oxidation in air. When applied as an anodic material for LIBs, the NiO@NCNR and NiO@NCNT hybrids exhibit a decent capacity of 895/832 mA h g −1 at 100 mA g −1 , high rate capability of 484/467 mA h g −1 at 5.0 A g −1 , and good long-term cycling stability of 663/634 mA h g −1 at 600th cycle at 1 A g −1 , which are much better than those of NiO@carbon black (CB) control sample (701, 214, and 223 mA h g −1 ). The remarkable electrochemical properties benefit from the advanced nanoarchitecture of NiO@NCNR and NiO@NCNT, which offers a length-controlled one-dimensional porous carbon nanoarchitecture for effective e − /Li + transport, affords a flexible carbon skeleton for spatial confinement, and forms abundant nanocavities for stress buffering and structure reinforcement during discharge/charging processes. The rational structural design and synthesis may pave a way for exploring advanced metal oxide based anodic materials for next-generation LIBs.

Self-Organized Growth of the Mo2C/Graphene Core-Shell Nanostructured Anode Material for Lithium-Ion Batteries via a Catalytic CVD Process

“…In addition to its role as a catalyst in the CVD growth of graphene, Mo 2 C has been considered a candidate material for energy storage device applications. − First-principles calculations predict a very fast diffusion of Li, Na, and K ions on intrinsically stable, metallic Mo 2 C. , Studies have shown that monolayer Mo 2 C as well as composite structures comprising of Mo 2 C and carbon nanomaterials (carbon nanotubes, graphene, reduced graphene oxide, and porous carbon) can be used as a promising anode material for Li-ion batteries. − , However, repeated electrochemical reactions cause the accretion of Mo 2 C particles, which decreases the active sites and hence results in poor cyclability and rapid capacity fading . As a solution to this issue, different strategies, such as the design of hybrid materials, carbon composition, nanostructuring, etc., have been implemented. , Embedding Mo 2 C into graphene layers can be considered an attractive strategy because this hybrid material can perform as a superior anode material with enhanced cyclability, Li + storage performance, surface area, electrical conductivity, chemical stability, and structural flexibility. , Recent studies have also demonstrated the enhanced electrochemical performance of various other composite anode and cathode materials, where metal oxides such as NiO, Co 3 O 4 , and LiFePO 4 have been wrapped with carbon-based nanostructures such as N-doped carbon nanoribbons and nanotubes, graphitic carbon nanotubes, porous nanocarbon, and so on. − In these composite or hybrid anodes, carbon materials serve as excellent coating layers, significantly improving the overall electrode performance and stability. While there are a few reports on the application of graphene/Mo 2 C hybrid nanostructures as an anode material for lithium-ion batteries, the exploitation of such hybrid material in thin film form for micro battery applications remains elusive.…”