Mesoporous LiFePO4 Microspheres Embedded Homogeneously with 3D CNT Conductive Networks for Enhanced Electrochemical Performance

• 3D CNT networks were uniformly embedded in mesoporous LFP microspheres.
• The porous structure could be well modulated by varying PEG molecular weight.
• Such hybrid structure can greatly enhance the electrochemical performance.
• The M-LFP/CNTs-400 with most abundant porous structure showed the best performance.

Mesoporous LiFePO4 (LFP) microspheres embedded homogeneously with three-dimensional (3D) carbon nanotube (CNT) conductive networks were successfully prepared via an effective and controllable hydrothermal approach with the assistance of polyethylene glycol (PEG). Scanning electron microscopy (SEM) and N2 adsorption–desorption characterization demonstrated that porous structure of these microspheres could be well modulated by varying the molecular weight of PEG. The LFP/CNTs composite prepared using PEG400, which possessed the best mesoporous structure with the pore size centered at 40 nm, and 3D CNT conductive network embedded in the microspheres homogeneously, exhibited the best electrochemical performance with high capacity retention of 95.7% even at 5 C after 100 cycles. Essentially, in comparison with those samples without mesoporous structure or CNT networks, this hybrid microstructure could not only greatly enhance the electrical conductivity, but also facilitate the electrolyte penetration into the microspheres, thus markedly improving the electrochemical performance.

Mesoporous LiFePO4 microspheres, whose porous structure could be well modulated by varying the molecular weight of PEG, have been embedded homogeneously with 3D CNT conductive networks by hydrothermal method. Such interpenetrative 3D CNT conductive networks and abundant porous structure can greatly enhance the electrochemical performance.Figure optionsDownload as PowerPoint slide