Improving the Capacity of Sodium Ion Battery Using a Virus-Templated Nanostructured Composite Cathode

In this work we investigated an energy-efficient biotemplated route to synthesize nanostructured FePO₄ for sodium-based batteries. Self-assembled M13 viruses and single wall carbon nanotubes (SWCNTs) have been used as a template to grow amorphous FePO₄ nanoparticles at room temperature (the active composite is denoted as Bio-FePO₄-CNT) to enhance the electronic conductivity of the active material. Preliminary tests demonstrate a discharge capacity as high as 166 mAh/g at C/10 rate, corresponding to composition Na_0.9FePO₄, which along with higher C-rate tests show this material to have the highest capacity and power performance reported for amorphous FePO₄ electrodes to date