Space-Confined Synthesis of Yolk–Shell Structured Co₃O₄/Nitrogen-Doped Carbon Nanocomposites with Hollow Mesoporous Carbon Nanocages as Advanced Functional Anodes for Lithium-Ion Batteries

Abstract

Despite the high theoretical capacity as the anode material of lithium-ion batteries (LIBs), Co 3 O 4 is subjected to rapid capacity decline and poor rate performance owing to its severe volume expansion and poor electronic conductivity. Herein, a yolk− shell structured Co 3 O 4 nanocomposite with double carbon shells (Co 3 O 4 @NC@CNC) was fabricated as an electrode material to improve the properties of LIBs. The Co 3 O 4 @ NC@CNC was derived from ZIF-67 within carbon nanocages (CNC) by carbonization. The hollow CNC acted as nanoreactors, which could effectively control the growth of ZIF-67 within the CNC and reduce the particle size of Co 3 O 4 @nitrogen-doped carbon (Co 3 O 4 @NC) nanocomposite derived from ZIF-67. When assessed as an LIBs anode material, the optimized Co 3 O 4 @NC@CNC material exhibited outstanding properties with high capacity, superior cycling stability, and rate performance (960 mAh g −1 at 0.5 A g −1 and 772 mAh g −1 at 2 A g −1 after 100 cycles). The electrochemical properties were ascribed to the yolk−shell structure and the synergistic effect of the nanoscale Co 3 O 4 @NC and CNC, which improved the electronic conductivity, alleviated the volume expansion effect, shortened the diffusion distance of Li + , and accelerated Li + transport kinetics. Moreover, the large specific surface and mesoporous structure were beneficial to the diffusion of electrolyte as well as capacitive contribution.

Mesoporous Carbon Materials for Electrochemical Energy Storage and Conversion

“…In charge‐discharge cycles, carbon shell or carbon skeleton type structures precisely confine the volume change of active materials particles while the mesopores and conductive walls provide efficient mass transport and fast charge transfer routes. These mesoporous structures can also serve as nanoreactors to regulate the in situ growth of active materials during the synthesis process, which can precisely downsize the active material NPs and further improve the anode electrochemical performance [115,118] . d), Utilizing the 2D carbon to synthesize sandwich‐like mesoporous structure [123,124] .…”

“…The performance of these electrodes was, therefore, be further improved compared to strategy a) [104,110–114] . c), Hollow MCs were served as nanocages to encapsulate active materials [36,55,69,105,115–122] . In charge‐discharge cycles, carbon shell or carbon skeleton type structures precisely confine the volume change of active materials particles while the mesopores and conductive walls provide efficient mass transport and fast charge transfer routes.…”

“…[104,[110][111][112][113][114] c), Hollow MCs were served as nanocages to encapsulate active materials. [36,55,69,105,[115][116][117][118][119][120][121][122] In charge-discharge cycles, carbon shell or carbon skeleton type structures precisely confine the volume change of active materials particles while the mesopores and conductive walls provide efficient mass transport and fast charge transfer routes. These mesoporous structures can also serve as nanoreactors to regulate the in situ growth of active materials during the synthesis process, which can precisely downsize the active material NPs and further improve the anode electrochemical performance.…”

“…These mesoporous structures can also serve as nanoreactors to regulate the in situ growth of active materials during the synthesis process, which can precisely downsize the active material NPs and further improve the anode electrochemical performance. [115,118] d), Utilizing the 2D carbon to synthesize sandwich-like mesoporous structure. [123,124] For instance, anchoring the active materials between nanosheets, such as forming C@TMO-rGO-TMO.…”

Facile Fabrication of Gold Nanorods@Polystyrenesulfonate Yolk–Shell Nanoparticles for Spaser Applications

“… 10 For example, space-confined synthetic approaches were used to obtain various types of yolk–shell particles. 11 − 14 Past studies have showed that different functional substances, such as therapeutic agents, can be incorporated into yolk–shell nanoparticles. 15 , 16 However, most of the current synthetic approaches involve multistep synthetic procedures, including thermal treatment and/or chemical etching.…”