Poly(styrene−butene/ethylene−styrene): A new polymer binder for high-performance printable lithium-ion battery electrodes

Abstract

Printed electrodes were developed by screen-printing from an ink formulation developed from a green solvent, a new polymer binder, and graphite (anode) or C-LiFePO4 (cathode). The morphological and electrochemical properties of the electrodes were investigated and compared to electrodes prepared with poly(vinylidene fluoride), PVDF, as a binder. The developed ink formulation shows similar processability and apparent viscosity of 0.09 and 0.07 Pa s at 100 s–1 for the cathode and the anode inks, respectively. The morphology for both electrodes is homogeneous, and in relation to the electrochemical performance, the discharge capacity value for the cathode film with poly(styrene–butene/ethylene–styrene) (SEBS) and PVDF binders is 137 and 53 mA h g–1 at C/5 and 113 and 29 mA h g–1 at 5C, respectively. The SEBS binder provides better mechanical stability and a more effective electronic conductive network. For the anode, the discharge capacity value with SEBS after 48 cycles is 177 mA h g–1 with a capacity retention of 78%. Thus, it is concluded that SEBS as a polymer binder shows adequate cycling performance, and the developed inks for the electrode films are suitable for printed lithium-ion batteries.