Virus-grown battery materials @ Massachusetts Institute of Technology

Author(s):

Angela Belcher, Gerbrand Ceder (MIT)

Widely used in small electronic devices and in the nascent market for HEVS (Hybrid Electric Vehicles), lithium ion batteries store more energy for theirweight, operate at a higher voltage, and hold a charge much longer thanother rechargeable batteries. As a new approach, Belcher and Ceder of the MIT MRSEC IRG-I have explored a biological way to create new charge storage materials for lithium ion batteries by using a virus as a scaffold totemplate the growth and assembly of nanoscale electrode materials. The genetically engineered M13 virus (E4 virus) successfully provided a platform for the growth of the amorphous iron phosphate, which can be used as a promising positive electrode material (top image). For electrochemical testing of the obtained amorphous iron phosphate, silver nano rods, which were also grown on separate E4 virus, were added as a conducting agent. The preliminary electrochemical data show that more than 120mAh/g of capacity (theoretical capacity of FePO4·2H2O is 140mAh/g) can be delivered. A small coin cell battery made from the virus-grown material powering an LED is shown in the bottom image. Because of self-replication, virus growth of nanomaterials can be easily scaled up as an effective way to fabricate novel battery materials.

Coin cell battery made from virus-grown material.

TEM image of an amorphous iron phosphate nanoparticle grown on a genetically engineered virus template.