Harnessing the power of microbes, Part 2 The Bio-battery

Sediment microbial fuel cells (SMFCs) are bioelectrochemical systems similar to Microbial fuel cells (MFCs) which generate electrical current using microbes. However, SMFCs use electrochemically active bacteria (EAB) found in marine sediments. In MFCs sediment is the limiting factor but for in situ SMFCs, this limitation is removed allowing for a theoretical continuous generation of electricity. Additionally, an electrical charge can be stored within the anode in these systems and can be released when needed producing bio-batteries.

Sudirjo et al (2019) studied the long term use and storage capacity of these SMFCs to create rechargeable bio-batteries. The key component was the use of activated carbon which offers itself a successful anode material that allows bacteria to grow within the porous structure and form biofilms as well as having the capacity to store electrons and thus enable the electrical power to be stored and released later. This paper offers a look into the use of these systems over long periods and theoretical use of these systems as ex-situ bio-batteries to store electricity and use them for off-grid purposes. Through the testing conducted it was calculated that this bio-battery would run for up to 21 years with minimal maintenance 

  

Strik, D., Buisman, C. J., & Sudirjo, E. (2019). Marine sediment mixed with activated carbon allows electricity production and storage from internal and external energy sources: a new rechargeable bio-battery with bi-directional electron transfer properties. Frontiers in microbiology, 10, 934.