High Capacity Hybrid Si-SWCNT Anode Structures for Li-Ion Batteries

In this presentation we describe structure, synthesis routes and electrochemical performance of hybrid Si-SWCNT composites developed by our team. We have investigated several approaches to the design of the silicon anodes to accommodate volumetric changes during charge and discharge of Si active material. Mass-produced single wall carbon nanotubes (SWCNTs) were used as a structural component in the 3D electrode matrix to provide mechanical support and conductivity path to deposited Si nano-beads. In other structures, layers of  SWCNT acted as a cushion accommodating volumetric changes of Si layers. Initial capacity of 2500mAh/g was achieved with good capacity retention up to 300 cycles. Advantages and shortcomings of several Si-SWCNT anode designs will be discussed.