Rechargeable, high energy density batteries are in demand due to the widespread and increasing use of portable electronic devices. Lithium-ion batteries are used most commonly due to their high performance, but are typically expensive to produce and often present safety risks. Various lithium-ion batteries have been generated, occasionally optimized for one aspect of performance over another (e.g., lower safety risk in exchange for decreased charge density). This advanced lithium-ion battery features an electrode composed of a cobalt oxide film. The film is assembled by bacteriophage (virus) particles and confers improved stability and capacity to the lithium-ion battery. It can be produced in a variety of shapes and sizes while retaining structural stability. Because the bacteriophage are easily reproduced in a bacterial host, it is also a cost-effective alternative to standard lithium-ion batteries.