By engineering a virus to pick up carbon nanotubes to create and grow the components required to make a battery.
Engineers at MIT discovered they can genetically alter viruses to collect materials to create the positive and negative ends of a lithium-ion battery. The new batteries’ characteristics can exact the performance of state of the art rechargeable batteries currently being used in hybrid cars and personal electronic devices.
The production of the batteries can also be manufactured cheaply without an environmentally damaging process. The synthesis of the battery “takes place at and below room temperature and requires no harmful organic solvents, and the materials that go into the battery are non-toxic” reports MIT.
Traditionally, lithium-ion battery utilizes lithium ions which flow between a negatively charged graphite anode and a positively charged cathode generally comprised of cobalt oxide or lithium iron phosphate. However, a team at MIT discovered a method to genetically alter viruses to self-assemble a nanowire after becoming an anode by collecting cobalt oxide and gold on themselves.
Self-assembling mechanism of modified M13 virus [Image Source: Jean-Marie Tarascon/Nature Nanotechnology]
According to MIT the battery is achieved by
“genetically engineered viruses that first coat themselves with iron phosphate, then grab hold of carbon nanotubes to create a network of highly conductive material. Because the viruses recognize and bind specifically to certain materials (carbon nanotubes in this case), each iron phosphate nanowire can be electrically “wired” to conducting carbon nanotube networks. Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time.”
The bacteria selected is a bacteriophage meaning it can only infect bacteria while remaining harmless to humans.
After the initial experiments of creating a viable but poorly performing battery, the team decided to introduce carbon nano tubes in an effort to increase the cathode’s conductivity without much addition of external weight. The new batteries created demonstrated some extraordinary characteristics as the batteries maintained a high energy density (~200 W h kg−1) and high specific power (~4.5 kW kg−1), enabling it as a potential candidate to be used within electric cars. Also, the batteries were able to achieve 100 charging cycles without losing much capacity. Although, after the initial 100 cycles, the performance begins to degrade far quicker than current lithium-ion batteries.
However, unfazed from the minor setback, the team decided to push forward with further experimentation. After the initial success of demonstrating the feasibility of creating a battery from a virus, perhaps a few more modifications could see the battery become more reliable and resilient to degradation making it an economically and environmentally friendly alternative to other methods of battery production. The new batteries could become the future power stores for electric cars and electronic devices.