Low cost carbon-silicon nanostructures for high performance electrochemical anode materials

N. Badi, J. Kodali, F.R. Hernandez, A. Okonkwo, M. Hobosyan, K.S. Martirosyan
University of Houston, US

Keywords: carbon nanostructures, hybrid carbon-silicon, ball-milling, batteries, ultra-capacitors, thin-film electrodes

Summary:

The current electrochemical based energy storage technology uses primarily activated carbon (AC) electrodes for their intended applications, which are indeed cost effective, scalable, but seriously lacks in performance for both higher surface area and high capacity lithium absorption. Carbon nanostructures (CNS) composed of CNT, graphene, graphitic carbon and carbon nanofibers come with outstanding properties and are most sought alternatives to replace AC material. Unfortunately, their synthesis cost makes them highly prohibitive. We have previously reported on fabricated anodes electrodes using pristine CNT, graphene, and carbon nanofibers which were synthesized using wet chemistry. This paper reports on successful production of CNS and hybrid CNS – silicon materials by thermomechanical mean. The CNS seems appropriate for applications as anode electrodes in electrochemical energy storage devices. Due to the nature of CNS blend, it exhibits large surface area that can be consolidated under different conditions to reach desired levels of porosity. Results on electrical conductivity measurements, specific capacity, energy density, efficiency, and cyclability in comparison to currently available AC counterpart will be presented. Methodologies which can facilitate the goal of creating a large-scale energy system that is cost effective and easily amenable to high volume manufacturing will also be discussed.