Session: 12-07-04: Mechanics of Soft Materials
Paper Number: 99935
99935 - Effect of Electrolyte on the Stress-Strain Behavior of Polymer Binder in Commercial Rechargeable Battery Electrode
Development of rechargeable batteries is critical for the success of renewable energy production technologies, this is because renewable energy sources such as solar and wind are intermittent sources of energy and they need energy storage devices to provide a continuous power supply. Lithium-ion rechargeable batteries are one of the prominent energy storage technologies available today. A typical commercial rechargeable battery consist of two electrodes namely, anode and cathode, and these electrode are immersed in a solution called electrolyte. A separator is placed between anode and cathode to avoid electrical contact allowing electrons to flow only through the external circuit. During charge/discharge process, the ions shuttle back and forth between these electrodes (i.e. anode and cathode). The commercial electrodes are in general composites made of active material particles which react with Li and responsible for energy storage, and these particles are held together and connected to a current collector by a polymeric binder. Since polymer binder is insulating, conductive additives are added to the binder to provide electronic conductivity and enable transfer of electrons throughout the electrode. Mechanical properties of the binder are critical for a successful operation of the rechargeable battery. Breaking of binder electrical network leads to an electrical isolation of particles, which is one of the mechanisms responsible for capacity loss. The role of binder becomes even more critical in the case of high performance electrodes which imparts significant stress on the binder. High performance group IV anodes e.g., Si undergo large volume expansion (~280%) compared to tradition carbon anode (~10%), which imposes significant stress and strains on binder network. The significantly high level of mechanical stresses are one of the primary reason for the failure of conventional binders in high performance-based composite electrodes. In order to understand and mitigate this degradation behavior due to this significant amount of stress, it is important to understand the mechanical behavior of the polymer binder. The importance of mechanical properties can be seen by the fact that using stiffer binders have shown to retain the capacity for more cycles. Stress-strain behavior of these binder has been characterized in the absence of electrolyte however, there is a need to understand how electrolyte soaking affects the mechanical behavior of polymer binder network. Hence, we characterized the mechanical behavior of a polymer binder in the presence of electrolyte. In this talk we will present the results from these experiments showing the effect of electrolyte on the stress-strain behavior of polymer binder.
Presenting Author: Martina Borges Michigan State University
Presenting Author Biography: Ph.D Student at Michigan State University
Authors:
Martina Borges Michigan State UniversitySiva Nadimpalli Michigan State University
Akshay Pakhare Michigan State University
Effect of Electrolyte on the Stress-Strain Behavior of Polymer Binder in Commercial Rechargeable Battery Electrode
Paper Type
Technical Presentation