Power battery structure and core components

Power batteries provide electric drive for new energy vehicles. They are not only heavy and complex in structure, but their performance is directly related to the vehicle's range, safety and power. They also largely affect the manufacturing cost of the vehicle. This article will take you to learn more about the structure and core components of power batteries. Let's learn together~

① Battery Cell

Battery cells are the basic units of power batteries, usually composed of positive electrode materials, negative electrode materials, separators and electrolytes.

►Positive electrode material: It is the main part of the battery that stores energy. Common positive electrode materials include lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, nickel cobalt manganese oxide (NCM) and nickel cobalt aluminum oxide (NCA). These materials can store lithium ions to generate current.

►Negative electrode material: It is the component that releases energy in the battery. Carbon materials (such as graphite) or other non-metallic materials are usually used. In lithium-ion batteries, negative electrode materials absorb lithium ions and release them to generate current. Common negative electrode materials include natural graphite, artificial graphite, hard carbon and soft carbon. Positive and negative electrode materials determine the chemical properties and energy density of the battery.

►Electrolyte: It is the medium that conducts ions in the battery, usually composed of organic solvents and electrolyte salts. The role of the electrolyte is to transfer lithium ions between the positive and negative electrodes, thereby realizing the energy conversion of the battery.

►Diaphragm: It is used to separate the positive and negative electrode materials to prevent short circuits while allowing lithium ions to pass through.

② Battery Module

The battery module is composed of multiple cells connected in series and parallel to achieve the required voltage and current levels to meet the energy needs of different electric vehicles (connecting cells in series can increase the total voltage, and connecting cells in parallel can increase the total capacity).

The battery module usually contains a battery management system (BMS), which is responsible for monitoring and managing the battery's charging and discharging process to ensure the safety and stable performance of the battery.

The battery module will also add a certain protective circuit board and shell to protect the battery and BMS, forming a combination that can directly provide electrical energy.

③ Battery Pack

The battery pack is a combination of multiple battery modules connected in series, and is the power battery assembly of electric vehicles. The battery pack also includes components such as electrical connections, cooling systems, and insulation protection to ensure the overall performance and safety of the battery pack. The battery pack is usually also equipped with safety protection measures, such as overheat protection, over current protection, short circuit protection, etc.

④ Battery Management System

BMS is responsible for monitoring the status of the battery, including monitoring voltage, current, temperature, insulation resistance, SOC estimation, SOH estimation and other programs. These programs perform calculations and analyses based on the data collected by the hardware to evaluate the status and health of the battery.

⑤ Other components

►Battery casing: protects the internal battery cells from the external environment and is usually made of metal or plastic.

►Cooling system: For high power density battery systems, additional cooling systems may be required to keep the battery temperature within the appropriate range to prevent overheating damage.

►Interfaces and connectors: used to connect batteries to other devices, such as chargers, loads, etc.

►Mounting components: such as brackets, trays, pressure rods, bolts, etc., used to fix and connect various components.

►Auxiliary components: such as sealing rings, rubber pads, sealants, buckles, cable ties, etc., used to ensure the sealing and connectivity of various components.

In summary, the composition of power batteries involves multiple aspects such as battery cells, battery modules and battery packs, battery management systems, and other auxiliary components. These components work together to enable power batteries to provide stable and reliable power support for electric vehicles. 

At the same time, the design and manufacture of power batteries need to meet the requirements of high safety, high energy density, long cycle life and low cost. With the development of technology, the composition and design of power batteries are also constantly optimized to meet the needs of the new energy vehicle market.