Rosin-Embedded Poly(acrylic acid) Binder for Silicon/Graphite Negative Electrode

We propose the use of a rosin-embedded poly(acrylic acid) binder, PAA-Rosin, to improve the cycling performance of silicon/graphite composites in lithium-ion batteries. Rosin, which is a natural product derived from pine trees, is chemically bonded with a rigid PAA polymer, which affords additional adhesion and elasticity of the PAA backbone, resulting in an effective binder with optimal properties. The hybridization of PAA-Rosin is achieved through an efficient one-step process, and the chemical structures of the components are systematically confirmed. In terms of the cycling performance, the cell based on PAA-Rosin shows excellent specific capacity retention (65.2%) with superior utilization of silicon/graphite composites even after 200 cycles. In addition, the PAA-Rosin electrode exhibits excellent specific capacity as well as remarkable capacity retention in bending tests. We demonstrate that the remarkable electrochemical characteristics of PAA-Rosin can be attributed to improved electrode uniformity, which results in the electronic networks remaining intact and minimizes electrode fatigue related to internal crack formation, delamination, and pulverization.