Fabrication and electrochemical properties of 3D nano-network LiFePO4@multiwalled carbon nanotube composite using risedronic acid as the phosphorus source  

作　　者：Liping Hea Wenke Zha Dachuan Chen 

机构地区：[1]State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body and College of Mechanical&Vehicle Engineering,Hunan University,Changsha,Hunan 410082,China [2]College of Civil Engineering,Hunan University,Changsha,Hunan 410082,China

出　　处：《Progress in Natural Science:Materials International》2019年第2期156-162,I0003,共8页自然科学进展·国际材料（英文版）

基　　金：supported by the “863” Hi-tech project from the Ministry of Science and Technology of China(NO.2008AA030905);the National Natural Science Foundation of China(NO.51073051 and NO.11701577);the Fund from the State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body(NO.71475003);111 Project(NO.B16015);the financial support from the Ministry of Science and Technology(NO.2016YFC07010308)

摘　　要：LiFePO4@multiwalled carbon nanotubes(LFP@MWCNTs)nanocomposite has been fabricated using risedronic acid(RDA)as a new eco-friendly phosphorus source.Microscopic,spectroscopic,and electrochemical characterization demonstrate that the MWCNTs are in the form of coiled and cross-linking nanoribbon,which wrapped and encrusted around LiFePO4 particles to form a three-dimensional(3D)nano-network composite.This microstructure of 3D nano-network is obtained due to the reactions between RDA’s special functional groups with Fe^2+and C-OH,-C=O or-COOH on the surface of the functionalized MWCNTs.The results also show that the particle size of the fabricated LiFePO4@MWCNTs composite is below 300 nm with the pure crystal of olivine.This nanocomposite indicates an enhanced reversible capacity of 162.2 mAh g^-1 at 0.2C,and high capacity retention of 76.5%even at 10C after the 800 th cycles.The electric conductivity and Li+diffusion coefficient(DLi^+)of the LiFePO4@MWCNTs are 3.79×10^-2S cm^-1 and 4.46×10^-11 cm^2s^-1,respectively.These improved electrochemical parameters can be attributed to the nano-sized effect of particles,MWCNTs’wrapping effect and 3D nano-network microstructure of the LFP@MWCNTs resulted from using RDA as a new phosphorus source.LiFePO4@multiwalled carbon nanotubes（LFP@MWCNTs） nanocomposite has been fabricated using risedronic acid（RDA） as a new eco-friendly phosphorus source. Microscopic, spectroscopic, and electrochemical characterization demonstrate that the MWCNTs are in the form of coiled and cross-linking nanoribbon, which wrapped and encrusted around LiFePO4 particles to form a three-dimensional（3D） nano-network composite.This microstructure of 3D nano-network is obtained due to the reactions between RDA’s special functional groups with Fe2+ and C-OH,-C=O or-COOH on the surface of the functionalized MWCNTs. The results also show that the particle size of the fabricated LiFePO4@MWCNTs composite is below 300 nm with the pure crystal of olivine. This nanocomposite indicates an enhanced reversible capacity of 162.2 mAh g-1 at 0.2C, and high capacity retention of 76.5% even at 10C after the 800 th cycles. The electric conductivity and Li+ diffusion coefficient(DLi+) of the LiFePO4@MWCNTs are 3.79 × 10-2S cm-1 and 4.46 × 10-11 cm2s-1, respectively.These improved electrochemical parameters can be attributed to the nano-sized effect of particles, MWCNTs’ wrapping effect and 3D nano-network microstructure of the LFP@MWCNTs resulted from using RDA as a new phosphorus source.

关 键 词：Risedronic ACID 3D nano-network ELECTROCHEMICAL properties LiFePO4@multiwalled NANOTUBE LITHIUM-ION battery 

分 类 号：TB3[一般工业技术—材料科学与工程]