Technical principle of fuel power lithium battery -Lithium - Ion Battery Equipment
A fuel power cell is usually composed of an electrolyte plate that forms an ionic conductor, a fuel electrode (anode) and an air electrode (cathode) configured on both sides, and a gas flow path on both sides. The purpose of the gas flow path is to enable fuel gas and air (oxidant gas) to pass through the flow path.
In the fuel pole, H2 in the supplied fuel gas is analyzed into H+and e -, and H+moves to the electrolyte to react with O2 supplied at the air pole side. E - Return to the air pole side via the external load circuit to participate in the reaction of the air pole side. The reaction of the first example enables the e - to continuously pass through the external circuit, thus forming the power generation. It can be seen from the reaction equation in the above equation that H2O generated by H2 and O2 has no other reaction, and the chemical energy of H2 is converted into electrical energy. But in fact, there is a certain resistance with the reaction of the electrode, which will cause some heat energy to germinate, thus reducing the proportion of electrical energy converted. The group of batteries that cause these reactions is called a module, and the voltage generated is usually less than one volt. Therefore, in order to obtain large output, it is necessary to adopt the method of multilayer superposition of components to obtain high voltage reactor. For the electrical connection between components and the separation between fuel gas and air, components called diaphragms with gas flow paths in the upper and lower sides are used. The diaphragms of PAFC and PEMFC are made of carbon materials. The output of the stack is determined by the product of the total voltage and current, and the current is proportional to the reaction area in the battery.
The electrolyte of PAFC is concentrated phosphoric acid aqueous solution, while the electrolyte of PEMFC is a membrane of proton conducting polymer system. The electrodes are made of porous carbon. In order to promote the reaction, Pt is used as the catalyst. CO in the fuel gas will cause poisoning and reduce the electrode performance. Therefore, in the use of PAFC and PEMFC, the CO content in fuel gas must be limited, especially for PEMFC working at low temperature.
The basic composition and reaction principle of phosphoric acid fuel power cell are as follows: the fuel gas or city gas is sent to the modifier after adding water vapor to convert the fuel into a mixture of H2, CO and water vapor, and CO and water are further converted into H2 and CO2 through catalyst in the shift reactor. The fuel gas thus solved enters the negative pole (fuel pole) of the fuel pile, and at the same time, the oxygen is delivered to the positive pole (air pole) of the fuel pile for chemical reaction. With the use of catalyst, electric energy and heat energy can be generated rapidly.
Compared with PAFC and PEMFC, high-temperature fuel power cells (MCFC and SOFC) do not need catalyst. Coal gasification gas with CO as an important component can be used as fuel directly, and it is also easy to use its high-quality exhaust gas to form combined cycle power generation.
MCFC main components. It contains electrolyte related to electrode reaction (usually carbonate mixed with Li and K), two electrode plates (fuel electrode and air electrode) connected with it up and down, and gas chambers and electrode clamps with fuel gas and oxidant gas flowing outside each electrode. The electrolyte presents molten liquid at the working temperature of about 600~700 ℃ of MCFC, forming ionic conductors. The electrode is nickel based porous body.