In the classification of battery usage scenarios, lithium-ion battery types are divided into consumer battery (3C batteries, used in mobile phones, notebook, digital cameras, etc.), power battery (new energy vehicles, light electric vehicles, electric tools, etc.), and energy storage system battery (power stations, communication base stations, etc.).
For power battery, it is actually a kind of energy storage system battery. However, due to the limitation of the size and weight of the car and the requirements of acceleration when starting, power battery has higher performance requirements than ordinary energy storage system battery, such as the energy density should be as high as possible, the charging speed of the battery should be fast, and the discharge current should be large.
Most energy storage devices do not need to move. As a result, the ESS lithium-ion battery has no direct requirements for energy density. As for power density, different energy storage scenarios have different requirements. It is used for electric peak-shaving, off-grid photovoltaic energy storage, or peak-to-valley energy storage scenarios on the user side. Generally, energy storage system batteries need to be continuously charged or continuously discharged for more than two hours, so it is suitable to adopt the capacity battery with charge-dischargie ratio of ≤0.5C ; For energy storage scenarios with electric power frequency modulation or smoothing fluctuations of renewable energy, energy storage system batteries need to be quickly charged and discharged in a time period of seconds to minutes, so they are suitable for applications of power batteries with ≥2C; however, in some application scenarios which need assume both frequency modulation and peak shaving, energy batteries are more suitable. Of course, power tool lithium batteries and capacity batteries can also be used together in this scenario.
Energy storage lithium batteries have higher requirements for service life. The life of new energy vehicles is generally 5-8 years, while the life of energy storage projects is generally expected to be longer than 10 years. The cycle number life of a power lithium battery is 1000-2000 times, and the cycle number life of energy storage lithium battery is generally required to be more than 3,500 times.
There are some differences between power lithium batteries and energy storage lithium batteries, but from the cell’s point of view they are the same, they both can use lithium iron phosphate batteries and ternary lithium batteries. The main difference lies in the BMS battery management system, the power response speed of the battery, power characteristics, SOC estimation accuracy, charge and discharge characteristics, etc., and they can all be implemented on the BMS.