Views: 12 Author: Site Editor Publish Time: 2024-03-18 Origin: Site
Energy storage lithium battery: Energy storage mainly refers to the storage of electrical energy, and energy storage lithium batteries mainly refer to lithium battery packs used in solar power generation equipment, wind power generation equipment, and renewable energy storage energy.
Power lithium battery: Power battery refers to the power source that provides power for tools, mostly referring to the lithium battery that provides power for electric vehicles, electric trains, electric bicycles, and golf carts. It usually has a large electrical capacity and output power, and the main source of power for new energy vehicles is power battery.
Both power battery and energy storage lithium battery are lithium batteries. Although there is no difference in technical principles between the two, due to different application scenarios, practical applications have different requirements for their performance and service life.
The energy density of different power battery is getting higher and higher, currently generally higher than 135Wh/kg.
For energy storage battery, the vast majority of energy storage devices do not require movement, so lithium energy storage batteries do not have direct requirements for energy density. As for power density, different energy storage scenarios have different requirements.
For power peak shaving, off grid photovoltaic energy storage, or peak valley price difference energy storage scenarios on the user side, the energy storage battery generally needs to be continuously charged or discharged for more than two hours. Therefore, it is suitable to use capacity type batteries with a charge discharge rate ≤ 0.5C; For energy storage scenarios with power frequency regulation or smooth fluctuations in renewable energy, the energy storage battery needs to be quickly charged and discharged in seconds to minutes, making it suitable for applications with ≥ 2C power type batteries; In some application scenarios that require both frequency modulation and peak shaving, energy type batteries are more suitable. Of course, in this scenario, power type and capacity type batteries can also be used together.
Power lithium batteries are mainly used in electric vehicles, electric bicycles, electric motorcycles and other electric equipment; It is also used in power transmission and transformation stations to provide closing current for power units; Due to limitations in the size and weight of automobiles, as well as requirements for starting acceleration, power batteries have higher requirements in terms of energy density, volume density, charge and discharge rate, battery safety, and higher costs.
Energy storage lithium batteries are divided into small household energy storage and large base station energy storage. Large base station energy storage is mainly used for peak shaving and valley filling with batteries, power grid frequency regulation, and rectification of hydraulic, wind, and photovoltaic systems.
Thanks to the rapid development of China's communication industry, small-scale energy storage in China is currently developing rapidly, including emergency backup power supplies in base stations, digital products, power products, medical and security, and household UPS power supplies.
In the power battery pack, BMS (Battery Management System) is the core, which determines whether the various components and functions of the battery pack can be coordinated and consistent, and directly relates to whether the battery pack can safely and reliably provide power output for electric vehicles. Of course, the connection process, spatial design, structural strength, and system interface of structural components also have an important impact on the performance of battery packs.
The BMS of electric vehicles has an energy exchange relationship with both the electric motor and charger on high voltage; In terms of communication, there is information exchange with the charger during the charging process, and in all application processes, there is the most detailed information exchange with the vehicle controller.
The energy storage battery management system is similar to the power battery management system, but the power battery system is located in a high-speed electric vehicle, which has higher requirements for the power response speed and power characteristics of the battery, SOC estimation accuracy, and the number of state parameter calculations. Relevant adjustment functions also need to be implemented through BMS.
In energy storage systems, lithium-ion batteries only interact with energy storage inverters on high voltage, which take power from the AC power grid to charge the battery pack; Alternatively, the battery pack can provide power to the inverter, which converts electrical energy into AC and sends it to the AC power grid.
For safety and economic considerations, when choosing a lithium battery pack for energy storage power stations, lithium iron phosphate batteries are often used, along with other batteries such as lithium cobalt oxide batteries.
The current mainstream battery types for power lithium-ion electric vehicles are lithium iron phosphate batteries and ternary lithium batteries.
Power lithium batteries focus more on charging and discharging power, requiring fast charging rate, high output power, and vibration resistance, especially emphasizing high safety and energy density to achieve long-lasting endurance, as well as lightweight requirements in terms of weight and volume.
The equipment for energy storage lithium batteries emphasizes battery capacity, especially operational stability and service life. It is important to consider the consistency of battery modules. In terms of battery materials, attention should be paid to factors such as expansion rate, energy density, and uniformity of electrode material performance, in order to pursue the long lifespan and low cost of the overall energy storage equipment.
