IGEM:IMPERIAL/2009/Biological battery

=Biological battery=

Description
A lithium ion battery is based around the transfer of lithium ions (Li+) from an anode to a cathode whe being charged and reverse when being consumed. The idea here is to create a bacterially-based cathode (and possibly even anode) by making the bacteria secrete the ions and then nucleate them in an encapsulation reaction

Cathode FePO4 - accepts Li ions and stores them in cathode, diffuses into the anode. Charge by moving from A to C. When not plugged in ions diffuse to A. Idea here is to change the cathode. Because we can encapsulate bacteria in solutions, coat each bacterium with this FEPO4 layer and place in matrix. Acts as a cathode in the system. Cheaper as you can grow your cathode

Take a flask, induce them to coat in FePO4 and concentrate/dry them into a tube. Put tube in Li ion solution.

Benefits

 * cheaper
 * less toxic
 * increased Li+ transport can enhance energy storage
 * production processes can be much more benign than the harsh chemistry normally needed

Bio-battery papers
dip a polymer electrolyte (conducts electricity) into a solution of engineered viruses. The viruses assemble into a uniform coating on the electrolyte. This coated electrolyte is then dipped into a solution containing battery materials
 * 1) Making cobalt oxide coating for anode


 * sciencemag.org/cgi/content/abstract/1122716v1

Because proteins that encapsulate the viruses recognise and bind specifically to certain materials such as carbon nanotubes in this case, each iron phosphate nanowire can be electrically ‘wired’ to conducting carbon nanotube networks (conducts electricity). Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time.
 * 2) Making iron phosphate coating for cathode

Electrically address electrode materials with poor electronic conductivity through nanoscale wiring of active materials

Specs
Cathodes Anodes

Phase 1 - Compounds/threshold/detection

 * Which chemical do we produce?
 * How do we produce the required chemicals for the encapsulation?
 * How much do we produce?
 * Is there a toxic level?

Phase 2 - Encapsulation

 * How long does encapsulation take?
 * What are concentrations required?
 * Which nucleation sequence on the membrane-bound protein is better?
 * How do we measure for successful nucleation?

Phase 3 - Killing strategy/gene deletion

 * Is it a really needed step in this project?
 * How do we measure for successful deletion?

Phase 4 - Storage

 * How do we create block cathodes that don't degrade: Biofilm?
 * How much Li+ do we put?

Phase 5 - Delivery

 * What technique are we going to use to make the bacteria into cathodes?

Issues to solve
How to conduct electricity for our model
 * 1) any conducting wire?
 * 2) clumping together of encapsulated cells? (eg biofilm?)
 * 3) Can the bacteria produce the FePO4 as at the moment it is essentially like a bead of FePO4.
 * 4) FePO4 is needed for the nanoparticle technology, but since we are using bacteria, can use different compounds? MnO?
 * 5) The battery limited by Li ions so it is a self regenerating (not self charging) battery.