In the classification of battery usage scenarios, batteries are divided into consumer batteries (3C batteries, used in mobile phones, laptops, digital cameras, etc.), power batteries (new energy vehicles, light electric vehicles, power tools, etc.), and energy storage batteries (power stations, communication base stations, etc.).
For power batteries, they are actually a type of energy storage battery. However, due to the size and weight limitations of automobiles and the requirements for acceleration during startup, power batteries have higher performance requirements than ordinary energy storage batteries, such as higher energy density, faster charging speed, and larger discharge current.
According to standards, power batteries with a capacity below 80% can no longer be used in new energy vehicles.
For energy storage batteries, most energy storage devices do not need to be moved, so energy density is not a direct requirement for energy storage lithium batteries. As for power density, different energy storage scenarios have different requirements.
For scenarios involving power peak shaving, off-grid photovoltaic energy storage, or peak-valley price difference energy storage on the user side, energy storage batteries generally need to be continuously charged or discharged for more than two hours. Therefore, capacity-type batteries with a charge/discharge rate of ≤0.5C are suitable. For energy storage scenarios involving power frequency regulation or smoothing of renewable energy fluctuations, energy storage batteries need to be rapidly charged and discharged within a time period of seconds to minutes. Therefore, power-type batteries with a charge/discharge rate of ≥2C are suitable. In some application scenarios that need to undertake both frequency regulation and peak shaving, energy-type batteries are more suitable. Of course, in such scenarios, power-type and capacity-type batteries can also be used together.
Compared to power lithium batteries, energy storage lithium batteries have higher requirements for lifespan. The lifespan of new energy vehicles is generally 5-8 years, while the lifespan of energy storage projects is generally expected to be greater than 10 years. The cycle life of power lithium batteries is 1000-2000 cycles, while the cycle life of energy storage lithium batteries is generally required to be greater than 3500 cycles.
In terms of cost, power lithium batteries face competition from traditional fuel-powered sources, while energy storage lithium batteries need to compete on cost with traditional peak-shaving and frequency regulation technologies. Furthermore, energy storage power stations are typically on the megawatt or even hundred-megawatt scale, therefore, energy storage lithium batteries require lower costs and higher safety standards than power lithium batteries.
There are some differences between power lithium batteries and energy storage lithium batteries, but from the perspective of the cells, they are the same. Both can use lithium iron phosphate batteries and ternary lithium batteries. The main difference lies in the BMS battery management system. The battery's power response speed and power characteristics, SOC estimation accuracy, charge and discharge characteristics, etc., can all be realized in the BMS.
