Water‐soluble Polyacrylate Copolymers as Green Binders of Graphite Anodes for High‐energy Density Lithium‐ion Pouch Cells with Enhanced Electrochemical and Safety Performance

Abstract

Water-soluble polyacrylate copolymers are developed as green functional binders of graphite anode to improve the performance of lithium-ion batteries (LIBs). Using five basic binders, it is demonstrated that the graphite plate with the alkanol acrylate crosslinker (type U20)-acrylic acid/acrylate copolymer (type LA138) composite binder (marked as Binder B) exhibits larger adhesive force, higher compaction density, and better electrolyte adsorption capacity compared to other plates with aqueous binders. In particular, the electrochemical performance of the batteries with Binder B is enhanced both at room temperature and low temperature, and retention capacity of 82.8 % at 1 C and 25 °C after 930 cycles and 91.3 % at 0.5 C and 0 °C are obtained. In addition, the batteries with Binder B also exhibit enhanced safety and heat stability. The enhanced performance is attributed to the good chemical stability of polyacrylate copolymers and unique film-forming properties. These results indicate that the graphite anode with aqueous Binder B has promising prospects for practical application, and it also provides a reference for solving the poor low-temperature performance of graphite anodes.

Achieving the Interface Stability of LiMn2O4 Cathode Using Aqueous Polyacrylic Acid/acrylate Copolymer and Nanoscale CaCO3 to Improve the High‐Temperature Cycling and Storage Performance of Lithium‐Ion Batteries

“…The peeling strength of the cathode plates was tested by the tensile tester (HY‐0580, Hengyi, Shanghai China) and the adhesion of several binders was evaluated. [ 34 ] The cathode plates were soaked in the electrolyte with 1 m LiPF 6 / in mixed ethylene carbonate (EC) and ethyl methyl carbonate (EMC) solvents (EC:EMC = 1:2 in weight, Shanshan, China) and placed in the thermostat at 60 °C for 72 h. The thickness and conductivity of cathode plates taken from the electrolyte were measured and compared with these of new cathode plates. A four‐probe conductivity tester (RTS‐8, 4Probes, Guangzhou China) was used to measure the resistance of the cathode plates.…”