Battery Energy Storage Category
There are a lot of energy storage system types in the world now,like Mechanical energy storage,Compressed air energy storage,Flywheel energy storage,Electrochemical energy storage etc,now we are talking about battery energy storage specifically.
1.Lead Acid Energy Storage
Principle: Lead-acid batteries are charged and discharged through the electrochemical reaction of lead and its oxides in sulfuric acid solution,electrical energy is converted into chemical energy storage when charging, and chemical energy is then converted into electrical energy and released when discharging.
Features: mature technology, low cost, high and low temperature performance, relatively low energy density,limited cycle life,usually around 500- 2000 times,there is a certain pollution to the environment, and it needs to be properly recycled.
2.Lithium Ion Battery Energy Storage
Principle: rely on the intercalation and de-intercalation of lithium ions between the positive and negative electrodes to achieve charge transfer,lithium ions come out of the positive electrode and are embedded in the negative electrode when charging,opposite when discharging.
Features: high energy density, can store more electrical energy, long cycle life, generally can reach 3000 – 8000 times,low self-discharge rate, high and low temperature performance is good,the cost is a little higher,but it needs a bms to detect and protect the battery,such as overcharge, overdischarge,or high temperature,which may cause safety problems.
3.Sodium-sulfur battery energy storage
Principle: Molten sodium and sulfur are used as electrodes to carry out electrochemical reactions through the conduction of sodium ions at high temperatures.
Features: High energy density,small size, short cycle life,up to 1000 – 2000 times,however,the operating temperature needs to be maintained at 300 – 350°C,which requires high thermal insulation and battery materials, and the chemical properties of sodium and sulfur are reactive at high temperatures, which poses a safety risk.
4.Flow battery energy storage
Principle: The electrolyte is stored in a storage tank outside the battery,electrolyte is pumped into the battery stack through a pump,redox reaction occurs on the surface of the electrode to achieve charge and discharge.
Features: Power and energy can be designed independently, long battery life, up to more than 1500 – 2000 cycles, high safety, electrolyte leakage is relatively less likely to cause serious consequences. However, the energy density is low, the footprint is large, and the system complexity is high.
5.Conclusion
Nowaday the Energy Storage Technology has been developed with many types,and we have many choice for it,but lead acid and Lithium battery energy storage is still the main solutions for Residential and Commercial as well as utility scale energy storage system because relatively this two Solutions is easier and convenient for installation and maintenance.