Electrochemical Properties of LiFePO4/C Composite Improved by High Energy Milling

2009 ◽  
Vol 620-622 ◽  
pp. 41-44 ◽  
Author(s):  
Chang Sam Kim ◽  
Sung Ik Hwang ◽  
Shin Woo Kim
Keyword(s):  
Particle Size ◽  
Electrochemical Properties ◽  
Sucrose Solution ◽  
Ultrasonic Spray Pyrolysis ◽  
Lithium Ion ◽  
High Energy ◽  
Milling Process ◽  
Spray Pyrolysis Method ◽  
High Energy Milling ◽  
Ultrasonic Spray

The electrochemical properties of LiFePO4 as a cathode of lithium ion batteries considerably depend on a particle size of LiFePO4 and a condition of carbon coating. In this study, LiFePO4 powders were prepared using ultrasonic spray pyrolysis method, and then LiFePO4/C composites were made by infiltrating sucrose solution into LiFePO4 powders, drying, high-energy milling and annealing. The effects of high-energy milling were analyzed by comparing with electrochemical properties of powders synthesized without high-energy milling. It was found that the milling process drastically reduced the particle size of synthesized powders and electrical conductivity, and improved discharge capacity, cycle stability and rate performance.

Microstructure and Electrochemical Properties of Post Heat-Treated Li(Ni1/3Co1/3Mn1/3)O2 Cathode Materials for Lithium Ion Battery

2006 ◽  
Vol 510-511 ◽  
pp. 1102-1105
Author(s):  
Seon Hye Kim ◽  
Kwang Bo Shim ◽  
Kyoung Ran Han ◽  
Chang Sam Kim
Keyword(s):  
Electrochemical Properties ◽  
Structural Characteristics ◽  
Ultrasonic Spray Pyrolysis ◽  
Lithium Ion ◽  
Spray Pyrolysis Method ◽  
Capacity Retention ◽  
Ultrasonic Spray ◽  
Heat Treated ◽  
Particle Size And Morphology ◽  
Size And Morphology

Li(Ni1/3Co1/3Mn1/3)O2 powders were synthesized by using an ultrasonic spray pyrolysis method, and then heat-treated at 900 or 1000°C for 20 h. The morphology of the as-synthesized powder was spherical. The post heat-treatment changed the particle size and morphology of the synthesized powders. Structural characteristics of the heat-treated powders were analyzed using XRD and SEM, and their electrochemical properties were compared. Higher first discharge capacity was obtained from the powder heat-treated at 1000°C, but its rough and rugged surface might cause a rapid decrease of the capacity retention.

Physical and Electrochemical Properties of SiOx /C Composites Prepared by a Combination of Spray Pyrolysis and High Energy Ball Milling

2015 ◽  
Vol 1775 ◽  
pp. 7-12 ◽  
Author(s):  
Anara Molkenova ◽  
Izumi Taniguchi
Keyword(s):  
Electrochemical Properties ◽  
Spray Pyrolysis ◽  
Ball Milling ◽  
Ultrasonic Spray Pyrolysis ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Potential Range ◽  
Composite Powders ◽  
Ultrasonic Spray ◽  
Energy Ball

ABSTRACTSpray pyrolysis has been widely used to prepare homogeneous and uniform ceramic powders with high purity. In this study, we are proposing ultrasonic spray pyrolysis followed by heat treatment to produce SiOx/C composite powders, where sucrose was used as a carbon source. Furthermore, high energy ball milling of the as-prepared powders in the presence of acetylene black was conducted to activate its electrochemical properties by reducing the particle size and improving the functionalization of the SiOx composite particles. SiOx/C nanocomposite finally obtained at a sucrous concentration of 0.1 mol L-1 showed superior electrochemical properties, and the SiOx/C nanocomposite electrode delivered the first discharge and charge capacities of 1252 and 819 mAh g-1, respectively, with an initial columbic efficiency of 65% at a current density of 50 mAh g-1 in the potential range from 0.01 to 3 V versus Li/Li+.

Electrochemical Properties of Al Doped Li(Ni1/3Co1/3Mn1/3)O2

2007 ◽  
Vol 124-126 ◽  
pp. 1023-1026 ◽  
Author(s):  
Seon Hye Kim ◽  
Kwang Bo Shim ◽  
Kyoung Ran Han ◽  
Chang Sam Kim
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Ultrasonic Spray Pyrolysis ◽  
Lithium Ion ◽  
Initial Discharge Capacity ◽  
Cycle Stability ◽  
Al Doping ◽  
Ultrasonic Spray ◽  
Initial Discharge

Al doped Li(Ni1/3Co1/3Mn1/3-xAlx)O2 (x=0.005, 0.01, 0.05) and Li(Ni1/3-x/2Co1/3Mn1/3-x/2Alx)O2 (x=0.01, 0.05) cathode materials for lithium ion batteries were synthesized using an ultrasonic spray pyrolysis and heat treatment. The substitution with Al reduced the content of Mn3+, promoted grain growth, and broadened the particle size distribution of synthesized powders. The initial discharge capacity of cells made with 0.5 mol% Al doped Li(Ni1/3Co1/3Mn1/3-0.005Al0.005)O2 powder was as high as that of the undoped (~180 mAhg-1, 3.04.5 V), and showed an excellent cycle stability. The improvement of the cycle stability was considered to be due to the decrease of Mn3+ in Li(Co1/3Ni1/3Mn1/3-xAlx)O2 by Al doping.

Sign in / Sign up

Export Citation Format

Share Document