Keywords: spherical graphene, Li-ion battery, High capacity, reversible, 1080 mAh/g, powder catalyst, CVD technique
Summary:Graphite-based energy storage devices, such as lithium-ion batteries (LIBs), are the most reliable energy storage devices for portable electronics, electric vehicles (EV) and electric grid storage due to their high energy density, high power density, stability, low cost, and safety. However, commercial LIBs still face some key challenges such as a short lifetime and low charging rate, and battery anode holds the solution of these issues. We present newly developed 3D spherical graphene structures that perform significantly high reversible capacities up to 1080 mAh/g (Fig.1) applied as an anode in LiBs cells. The technology of producing this graphene material is used the cost-efficient Chemical Vapor Deposition technique and commercial powders of Copper alloys (bronze, brass). Few-layer (2-6 layers) graphene decomposes on the micron-sized spherical catalyst at high temperatures (800-900˚C) by applying Hydrocarbon source. The spherical shape of catalyst leads in misorientation within adjacent graphene layers after catalyst removal. The size of spheres varies from few nanometers up to micron sizes. Our study reveals that interlayer interaction of misoriented layers is considerably weaker which seems the key factor enabling full diffusion Lithium within interlayer spaces and stable cycling of LIBs cells with high charge-discharge efficiency. We study the feasibility of this technology and our goal is to scale-up and commercializes of new spherical graphene as an advanced anode for next-generation high energy density and high power density secondary batteries. An effective capacity increase of over 400% compared to commercial graphite cells promises the development of lightweight, cost-efficient, new-generation batteries. Relevant Publications 1. T. M. Paronyan, A.K. Thapa, A. Sherehiy, J. Jasinski, J.S. Dilip, Incommensurate graphene foam as a high Capacity Lithium intercalation anode. NATURE, Sci. Rep. 7, 39944; doi: 10.1038/srep39944 (2017). 2. T. M. Paronyan “Advanced graphene anode for the Li-ion batteries”- review for Dekker Encyclopedia of Nanoscience and Nanotechnology-just accepted. 1. T. M. Paronyan, A. K. Thapa, A. Sherehiy, J. B. Jasinski, J. S. Dilip- Exceptional Lithium Intercalation Capacity of Incommensurate Graphene Foam in Rechargeable Batteries- ECST V77. p311-320 (2017) 2. T. M. Paronyan, A.K. Thapa, A. Sherehiy, J. Jasinski, J.S. Dilip, Novel Graphene Structures: Substantial Capacity Enhancement in Lithium Batteries- Advanced Materials TechConnect Briefs Graphene & 2D-Materials Chapter 3, pp. 95-98 (2017).