The results show that the LiMn2O4 cathode with PAA/NMP system displays the best cycle performances at both 25 C and 55 C among these four cathodes; the better capacity retention for LiMn2O4 cathode with PAA/NMP system is related to strong binding ability, appropriate swelling property and homogeneous distribution of particles inner the electrode.

Abstract
Physical and chemical properties of poly(vinylidene fluoride) (PVDF), sodium carboxymethyl cellulose
(CMC) and polyacrylic acid (PAA) binders are investigated in this paper, including functional group
analysis, crystallinity and thermal properties. Then LiMn2O4 cathodes with four different binder systems
(PAA binders/NMP solvent, PVDF binders/NMP solvent, PAA binders/H2O solvent and CMC binders/H2O
solvent) are prepared, and their adhesion strengths, swelling properties, morphologies and electrochemical properties are studied. The results show that the LiMn2O4 cathode with PAA/NMP system displays the best cycle performances at both 25 C and 55 C among these four cathodes; the better capacity retention for LiMn2O4 cathode with PAA/NMP system is related to strong binding ability, appropriate swelling property and homogeneous distribution of particles inner the electrode.

Materials

PAA powder (Mw ¼ 450,000) was purchased from SigmaeAldrich. PVDF (HSV900, Mw ¼ 1,000,000) was supplied by Arkema, France. The
type 2200 sodium carboxymethyl cellulose (CMC) was come from DAICEL, Japan.

Article Info

A comparative study of different binders and their effects on electrochemical properties of LiMn2O4 cathode in lithium ion batteries
Zhian Zhang a,b, Tao Zeng a, Yanqing Lai a,b, Ming Jia a,b, Jie Li a,b,*
a School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China
b Engineering Research Center of High Performance Battery Materials and Devices, Research Institute of Central South University in Shenzhen, Shenzhen 518057, China
Article history:
Received 26 March 2013
Received in revised form
17 July 2013
Accepted 14 August 2013
Available online 27 August 2013
Keywords:
LiMn2O4 cathode
Binder
Properties comparisons
Polyacrylic acid