Life Cost Assessment of Using Binders of Sulfide-Based All Solid-State Lithium Batteries for Lithium-Ion Batteries

PVDF is commonly a binder used for cathode materials in generation 3 Li ion batteries due to the good binding ability to active material and the current collector with reasonable electrochemical stability and maintaining facile lithium transport. However, organic solvent N-methyl pyrrolidone (NMP) is required for the preparation of slurry in order to dissolve PVDF [1]. These drawbacks of high cost and environmental issues are worsened by the fact that PVDF can easily react with components of liquid electrolytes with possible formation of LiF leading to the unstable performance [2]. Furthermore, fluorinated polymers are considered an environmental risk and are a major concern for recycling efforts [3]. Therefore, reducing the use of polyvinylidene difluoride binder in combination with toxic and expensive N-methyl pyrrolidone (NMP) organic solvent, resulting in safe use and utilization during the battery manufacturing process, is the aim of this work. Here, the sulfide solid state binders are attractive candidates for the anode and cathode composites from the point of view of environmentally friendly use of materials, low cost, and easy electrode processing with subsequent disposal. This study reports the performance of the cathode and anode materials applied to these types of binders and reference binders of polyvinylidene difluoride (PVDF) for these as-obtained samples for lithium-ion batteries. The obtained cathode and anode materials are analyzed by XRD and SEM methods. The electrochemical performance of the obtained electrodes is tested by galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. The obtained electrodes exhibit stable electrochemical performance due to the better uniform distribution of electrode particles with strong adhesion to the current collector for long cycle life and stable formed SEI layer compared to the PVDF-based sample. In addition, these samples maintain stable cycle life after various rate capabilities due to the facilitated lithium-ion diffusion and electronic conductivity.

Acknowledgments

This work was supported by the financial support of the Austrian Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology.

References

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