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

AbstractWater‐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.