Lithium battery energy storage advantages and main technology

Source: 2020 - 04 - 11 eliakim hits: lithium battery energy storage and the type of energy storage technology and main technology advantages at present, the existing pumping, flywheel energy storage technologies including physical energy storage, such as electromagnetic energy storage, such as the super capacitors based on electrochemical principle of battery energy storage, etc. Discharge to consider factors such as time, cost, battery become photovoltaic power plant energy storage [ 1] The first choice. The existing including lead-acid batteries, lithium batteries and battery full vanadium flow batteries. Lead-acid battery has a history of more than one hundred years, because of its low cost, stable performance and is widely used. But the cycle life of lead-acid battery is low, the general is 300 - 600 times; In addition, the lead in the battery manufacture, use and recycling process caused by the pollution of the environment is not acceptable to the modern society. 所有- - - Vanadium flow batteries is a new type of energy storage battery, the power of it depends on the area of individual, pile layer number and the number of series and parallel and ability depends on the volume of electrolyte, suitable for large capacity storage, almost no self-discharge, long cycle life. All vanadium flow batteries are expensive, the conversion efficiency and stability need to be improved. In addition, the vanadium flow batteries need a pump to control fluid, increased [ 2] The cost of. Lithium battery voltage is high, wide working temperature range, than can high efficiency, low self-discharge rate. Thus, according to the advantages and disadvantages of all kinds of batteries, lithium-ion batteries for its relatively mature industry chain, safe and reliable, environmental protection etc. , be the first choice of the energy storage power station. Li-ion battery management system (li-ion battery energy storage key technologies BMS) Is the essential system of lithium electricity work. First of all, the lithium battery are not allowed to overcharge and over discharge, so must be equipped with protection devices, to ensure the safety of all cells. On the other hand, the nominal voltage of the single lithium battery is only 3. 2 - 3. 7 v, i. e. , apply to all kinds of load, must be combined in series and in parallel; Due to the difference between monomer battery, battery performance showed a trend of decline, such as significantly lower than the monomer battery service life. Therefore, a complete BMS system should not only include protection technology, but also reasonable balance for specific applications, the difference between each lithium battery unit fluctuations within a reasonable range, ensure the battery pack [ 3] The safe and efficient work. SOC can accurately said the remaining battery capacity. Reasonable battery SOC estimation is prediction work time, to avoid a charge discharge premise, is one of the basic function of BMS. Because of the complexity of the battery model, SOC estimation is very complex, the commonly used method has its rationality, but there are a lot of defects. Temperature also is the important factors that influence working efficiency of lithium battery. Temperature on the battery discharge capacity, internal resistance, and has great effect on the open circuit voltage. Especially under the low temperature, discharge capacity can even drop to about half that of room temperature. Therefore, a complete BMS system should also have intelligent temperature control function, extending application environment [ 5] 。