What is an energy storage battery? What is a power battery?

Energy storage batteries and power batteries are important technologies in the field of energy storage and electric transportation today. Essentially, both types of batteries belong to energy storage batteries and there is not much difference in their technical routes.

What are the differences between these two types of batteries? Can it be mixed? This article provides an introduction and analysis to help everyone better understand the specific differences between the two types of batteries.

What is an energy storage battery?

Energy storage batteries, as the name suggests, are battery systems used to store electrical energy. They can convert electrical energy into chemical energy, store charges in batteries, and then release them when needed. Energy storage batteries are usually designed for long-term energy storage and charging/discharging, playing an important role in power grid scheduling, peak load reduction, and energy management. The key characteristics of energy storage batteries are high capacity, long cycle life, and stable performance.

What is a power battery?

Power batteries are specifically designed to provide the power required for electric vehicles. They need to have high energy density and high power output to meet the requirements of electric vehicles for acceleration performance and driving range. The design focus of power batteries is to improve their charging speed, discharge speed, and cycle life. Meanwhile, safety is also an important aspect of power batteries to ensure reliable operation under various conditions.

Further explore the main differences between energy storage batteries and power batteries, which are mainly reflected in the following points.

Application scenarios

Energy storage batteries are widely used in fields such as power grid energy storage, household energy storage, industrial and commercial energy storage, communication base stations, etc. The design requirements of energy storage batteries mainly focus on optimizing energy density and long-term storage to meet the needs of large capacity and long-term energy storage. Due to the fact that the vast majority of energy storage devices in energy storage batteries do not require movement, lithium energy storage batteries do not have a direct requirement for energy density; Different energy storage scenarios have different requirements for power density; 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 service life and low cost of the entire energy storage equipment.

Power batteries are applied to new energy passenger vehicles, commercial vehicles, special vehicles, engineering machinery equipment, ships, etc. Power batteries focus more on power density and short-term high power output to meet the needs of electric vehicles for fast acceleration and long mileage. Compared to energy storage batteries, power batteries require higher energy density and power density. Furthermore, due to the limitations of car size, weight, and acceleration during startup, power batteries have higher performance requirements than ordinary energy storage batteries.

System composition

The power battery pack basically consists of the following 5 systems: battery module, battery management system, thermal management system, electrical system, and structural system. The cost of the power battery system consists of comprehensive costs such as battery cells, structural components, BMS, box, accessories, and manufacturing costs. Battery cells account for about 80% of the cost, while Pack (including structural components, BMS, box, accessories, manufacturing costs, etc.) costs account for about 20% of the entire battery pack cost.

The energy storage battery system mainly consists of battery packs, battery management systems (BMS), energy management systems (EMS), energy storage inverters (PCS), and other electrical equipment. In the cost composition of energy storage systems, batteries are an important component, accounting for 60% of the cost; Next are energy storage inverters, accounting for 20%, EMS (energy management system) costs accounting for 10%, BMS (battery management system) costs accounting for 5%, and others accounting for 5%.

Battery BMS

The BMS (Battery Management System), as the core component of the battery system, 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. 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.

Number of cycles

Power batteries and energy storage batteries have different requirements for their service life. Energy storage batteries typically require a longer cycle life and can withstand thousands of charge and discharge cycles without significantly reducing performance.

Taking electric vehicles as an example, the theoretical lifespan of a ternary lithium iron phosphate battery pack is 1200 times. Based on the frequency of complete charging and discharging every three days, the lifespan of a ternary lithium battery can reach ten years.

Compared to power batteries, energy storage batteries charge and discharge more frequently. Under the same 10-year lifespan, they have higher requirements for cycle life. If energy storage stations and household energy storage batteries charge and discharge once a day, the cycle life of energy storage lithium batteries is required to be greater than 3500 times. If the charging and discharging frequency is increased, the cycle life is usually required to be more than 5000 times.

Battery cost

Cost is also one of the differences between the two. The cost of energy storage batteries is relatively low because they use more mature battery technology and the application conditions are relatively simple, which can achieve economic benefits in large-scale applications.

In contrast, the cost of power batteries is relatively high, mainly due to the requirements for high energy density and high power output, as well as the need for long battery life and high safety.

Can energy storage batteries and power batteries be mixed together?

Energy storage batteries cannot be used in electric vehicles as there are differences in magnification, internal resistance, capacity, and voltage between the two. Energy storage batteries generally have higher energy density, but lower power density. For example, if the discharge temperature exceeds 0.5C at 280, the temperature will be too high. Therefore, energy storage batteries cannot be used as power lithium batteries.

Power lithium batteries can be used as energy storage batteries, and it is necessary to understand the control system of the design configuration for the discharge size of lithium batteries. However, both power batteries and power control systems have high cost factors, which can lead to less than ideal economic benefits.

It is understood that energy storage lithium batteries also have power types, such as supporting stable current discharge capacity of around 5C, which are widely used in frequency modulation. Some companies will reuse retired power batteries as energy storage batteries for household and mobile energy storage applications.

Shenzhen Gitenno Technology Co., Ltd. is an international innovative high-tech enterprise specializing in the research and development, manufacturing, and sales of lead-acid batteries. After several years of development, has grown into one of the manufacturers of high-quality lead-acid batteries in China.