Multi-Wall Carbon Nanotube-Embedded Lithium Cobalt Phosphate Composites with Reduced Resistance for High-Voltage Lithium-Ion Batteries

作者：Kim Tae Kyoung; Rustomji Cyrus S; Cho Hyung Man; Chun Dongwon; Jung Jae Young; Caldwel Elizabeth; Kim Youngjin; Han Jun Hyun; Jin Sungho^*

来源：Electronic Materials Letters, 2016, 12(1): 147-155.

DOI：10.1007/s13391-015-5310-8

• lithium cobalt phosphate
• carbon nanotube
• embedded structure
• nano-composite
• charge transfer resistance
• lithium-ion battery

Lithium cobalt phosphate (LCP) is a high-voltage cathode material used in high-energy-density lithium-ion batteries. With a novel composite synthesis method, multi-wall carbon nanotube (MWCNT)-embedded LCP nanocomposites (LCP-CNT composites) are synthesized to enhance the electrical conductance of LCP particles, reducing charge-transfer resistance. The LCP-CNT composites with enhanced electrical conductance approximately doubled cell capacity compared to a cell with a bare LCP cathode. The crystal structure of LCP-CNT composite particles is characterized by X-ray diffraction; the microstructures of the embedded MWCNTs inside LCP particles are confirmed by transmission and scanning electron microscopy with focused ion beam procedures. Electrochemical impedance spectroscopy shows the charge-transfer resistance of the cell with the LCP-CNT composite (1.0 wt. % CNT) cathode decreases to similar to 80 Omega, much smaller than the similar to 150 Omega charge-transfer resistance of the bare-LCP cathode cell. Based on battery test and impedance analysis, the main factors affecting the capacity increment are the reduced charge transfer resistance and the uniform distribution of MWCNTs, which is formed during the gelation step of the LCP synthesis procedure.

• 出版日期2016-1