Coal, oil and natural gas are the main energy sources of human life at present. With the development of human society and the improvement of living standards, the energy consumption is increasing day by day. These energy materials endowed by nature are gradually accumulated through thousands of years of crustal changes. Although the number is large, it is limited after all. Therefore, people will eventually face the day of energy crisis.

Of course, people can get energy in many ways. For example, solar energy is a huge energy source. In addition, geothermal, hydraulic and nuclear fission can release a lot of heat energy. Experimental research shows that the use of microbial power generation shows people a bright future.

There are many kinds of batteries, and fuel cells are the rising stars of this family. Generally, a battery consists of a positive electrode, a negative electrode and an electrolyte, and so does a fuel battery: the fuel reacts chemically at one end of the negative electrode and loses electrons; Let the oxidant react at one end of the positive electrode and let the electrons run from the negative electrode through the wire. Just like an ordinary battery, there is current flowing in the wire at this time.

The fuel cell can use hydrogen, hydrazine, methanol, formaldehyde, methane, ethane, etc. As fuel, there are oxygen, air, hydrogen peroxide and so on. As an oxidant. Now we can use the so-called "electrode active substances" produced by microbial life activities as battery fuel, and then convert chemical energy into electrical energy by a method similar to fuel cells, thus becoming microbial batteries.

As electrode active substances of microbial batteries, hydrogen, formic acid, ammonia, etc. are the main materials. For example, many hydrogen-producing bacteria have been found, including more than 30 chemotactic heterotrophic bacteria. They can ferment carbohydrates, alcohols, organic acids and other organic substances, absorb chemical energy from them to meet the needs of their own life activities, and release another part of energy in the form of hydrogen. Using this hydrogen as fuel, hydrogen-oxygen microbial batteries can be manufactured.