What are the factors affecting the price of lithium batteries?
1. Lithium battery price composition
The price of a lithium battery is mainly composed of three major components: the battery cell, the PCM, and the shell.
At the same time, due to the power consumption and current of the electric appliance, the material of the connection sheet between the battery cells (conventional nickel sheet, molded nickel sheet) , Copper-nickel composite sheet, jumper sheet, etc.) will affect the cost, different connectors (such as aviation plugs, ranging from more than ten yuan to thousands of yuan) may also have a greater impact on the cost, there is Different PACK processes will also affect the cost.
2. Factors influencing the price of lithium batteries
1. Selection of batteries
First, the selection of batteries with different material systems will affect the price of the entire lithium battery. Lithium batteries will have lithium manganese oxide (3.6V), lithium cobalt oxide (3.7V/3.8V), lithium nickel cobalt manganate (commonly known as ternary, 3.6V), and lithium iron phosphate (3.2V) depending on the cathode material. , Lithium titanate (2.3V/2.4V) and other battery cells with different material systems, the voltage platform, safety factor, number of cycles, energy density ratio, working temperature, etc. are different for the cells of different material systems.
The second is that the prices of batteries of different brands will also vary greatly. The total price gradient can be divided into: special batteries (including ultra-low temperature, ultra-high temperature, ultra-high rate, special-shaped), Japanese (Panasonic, Sanyo, Sony), Korean Series (Samsung, LG), domestic (domestic is divided into first-line (Lishen, BAK, BYD, ATL), second-line, even five-line, six-line), the same material system but different brands of batteries, prices The difference will also be very large, and the quality (safety, consistency, stability) of the battery cells of each brand through the survival of the fittest in the market is basically proportional to the price.
2. Demand and design of lithium battery PCM
PCM design can be divided into: basic protection, communication, BMS
Basic protection: basic protection includes over-charge, over-discharge, over-current and short-circuit protection, and over-temperature protection can be added according to product needs
Communication: The communication protocol can be divided into I2C, RS485, RS232, CANBUS, HDQ, SMBUS, etc. There is also a simple power display, which can be indicated by a power meter and LED.
BMS: BMS is the first letter abbreviation combination of BATTERYMANAGEMENTSYSTEM, called the battery management system, commonly known as battery nanny or battery housekeeper, mainly for the intelligent management and maintenance of each battery unit, to prevent the battery from overcharging and overdischarging. Extend battery life and monitor battery status. Its main functions include: real-time monitoring of battery physical parameters; battery state estimation; online diagnosis and early warning; charge, discharge and precharge control; balance management and thermal management, etc. The secondary system is mostly used in electric vehicle batteries.
3. Demand and design of lithium battery casing
Lithium battery shell design can be divided into: PVC heat sealing, plastic, metal
PVC heat-sealing: What kind of shell encapsulation type is used for the exterior of the battery pack depends mainly on the specific needs of the customer’s product. For the packaging type that uses PVC heat-sealing, it is generally suitable for a small number of battery cells in series and lighter overall weight. (≤2kg), it can be used. However, for battery packs with an overall weight of ≥1kg, it is necessary to add a fixing bracket between the cells, and to protect the periphery with a glass fiber board, and then use PVC heat sealing.
Plastic: Plastic shell is used, mainly after different battery packs are shaped, the shell involved may need to be moulded, and the mould cost is a large expense. If the product is not finalized in the early stage of development, you can use the prototype shell for proofing (prototype) The strength is not as good as the strength of the material after the mold is opened and shaped), and the requirements for the material and technology of the shell (especially with three-proof requirements) are different, which will also affect the cost.
Metal: The metal shell is also the same as the plastic shell. Before the product is finalized or the quantity demand is not large, it is recommended to use sheet metal sample preparation. This is mainly because the sample preparation and delivery time is short. If the batch is large, it is also recommended to open the mold. For metal shells that have a waterproof level requirement, it will also greatly affect the cost, and for metal shells with special materials (such as titanium alloys, etc.), the cost will be higher.
The cost of a lithium battery is mainly composed of batteries, PCM, and structural parts. In addition, the company's PACK costs, aging costs, and management costs must be added. At the same time, due to the different requirements of product technical difficulty, purchase amount, and defective rate, the price of lithium batteries will vary greatly!