The invention relates to a microbattery made of bioelectroactive components based on biomimetic processes. Bio-derived electron donors and electron acceptors are separately encapsulated in at least one pair of polymerized phospholipid vesicles. Embedded within the vesicle walls are lipophilic electron mediators that facilitate the transfer of electrons across the vesicle walls. Each pair of vesicles is immobilized on a conducting surface. The pair of vesicles are isolated from each other to create a galvanic cell, in which electrons flow from high to low electrochemical potential. A high energy density battery can be achieved if the vesicles are immobilized on highly porous conducting substrates.