22 Years' Battery Customization
Nov 23, 2019 Pageview：6052
The price of lithium battery mainly consists of cells, protective board and shell. The power consumption and current of electric appliances, the material selection of battery connection (conventional nickel sheet, forming nickel, copper nickel composite plate, jumper, etc.) will affect the cost. Different connectors (such as thespecial plug, from ten yuan to thousands yuan) may also affect the cost, and different PACK process will also make a difference.
The selection of cells of different material systems will affect the price of lithium battery. According to different anode material of lithium-ion batteries, there is lithium manganese (3.6 V), lithium cobalt oxides (3.7 V / 3.8 V), NCM (commonly known as ternary battery, 3.6 V), lithium iron phosphate (3.2 V), lithium titanate (2.3 V / 2.4 V), and other material system of batteries. The batteries with different material system have different voltage platform, safety coefficient, recycling times, energy density ratio, temperature, etc.
Different brands of batteries have different price. The total price gradient can be divided into: special batteries (including super low temperature, super high temperature, super high rate, abnormal one), Japanese brand (Panasonic, Sanyo, Sony), South Korea brand (Samsung, LG), domestic brand (Chinese brand is divided into premium brand (Lishen, Bick, BYD, ATL), the second-tier brand, or even can be assigned to the fifth-tier brand, sixth-tier brand). Batteries with the same material system but different brands will have different prices. The quality of each brand batteries after marketing evolution (security, consistency and stability) is basically proportional to the price.
PCM design can be divided into basic protection, communication and BMS.
Basic protection: basic protection includes over charge, over discharge, over current and short circuit protection. It can provide over temperature protection according to product requirement.
Communication: communication protocol can be divided into I2C, RS485, RS232, CANBUS, HDQ, SMBUS, etc., as well as simple power display, which can be indicated by power meter LED.
The main purpose of the Battery management system is to intelligently manage and maintain each battery unit, prevent the over-charging and over-discharging of the battery, extend the battery life and monitor the condition of the Battery. Its main functions include: real-time monitoring of battery physical parameters, battery state estimation, online diagnosis and early warning, charge, discharge and pre-charge control, balanced management and thermal management, etc. The secondary system is mainly used in electric vehicle batteries.
Lithium battery shell design can be divided into: PVC heat seal, plastic and metal.
PVC heat seal: the specific type of outer shell package used for the battery pack mainly depends on the specific requirements of customer. PVC heat seal package is generally applicable to small amount batteries with relatively light weight (≤2kg). However, if the battery pack with the overall weight ≥1kg, it is necessary to make a fixed bracket between the batteries, and use PVC heat seal after the fiberglass board protection.
Plastic: Different battery pack needs open mold after finalize the design, and the mold fee is high. For example, using hand model for sampling if the product mold did not finished at the early stage of the development (the material strength of hand mold is worse than that of open mold) has different requirements on the material and process of shell (especially with three-proofing), and will also affect the cost.
Metal: The metal shell is the same as the plastic shell. If product is not finalized or has less quantity demand, it is recommended to use sheet metal sample, so that the sample delivery time is short, and large batch is also recommended for open mold. If the metal shell has the waterproof level requirements, it will also greatly affect the cost, and special material (such as titanium alloy, etc.) metal shell requirements will have higher cost.
The cost of lithium battery is mainly composed of battery cell, PCM and structural parts. In addition, PACK cost, aging cost and management cost should be included. Due to the product technical difficulty, purchase amount and different defect rate requirements will affect lithium battery prices greatly.
As for the perspective of lithium battery composition, it mainly includes anode material, cathode material, electrolyte and separator. Generally, anode materials account for 40%-46% of the total cost of lithium battery, which is the most important part in the lithium battery industry chain. The cost of each component is shown in the following table.
| Lithium battery cost composition | Lithium battery cost composition |
| Anode material | 40%-46% |
| Cathode material | 5%-15% |
| Electrolyte | 5%-11% |
| Separator | 10%-14% |
| Other(packing material) | 18%-36% |
As for the technical difficulty of the product, separator, anode material and electrolyte have a certain technical barriers, while the cathode material is relatively simple, and the supply expands fast.
At present, the main technology route of anode materials includes lithium cobalt oxide, lithium manganese oxide, NCM (commonly known as ternary material) and lithium iron phosphate. The main new energy vehicle models tend to use ternary materials and lithium iron phosphate materials.
If the battery PACK was a human body, the module was the "heart" that stored and released the energy that powered the car. Lithium battery module is composed of several to hundreds of battery cells in parallel and series. In addition to the mechanism design, the battery management system and thermal management system can form a complete lithium battery package system.
The structural system is mainly composed of the top cover, tray, various metal supports, end plates and bolts of the battery PACK, which can be regarded as the "skeleton" of the battery PACK, playing the role of support, resistance to mechanical shock, mechanical vibration and environmental protection (waterproof and dustproof).
The electrical system mainly consists of high-voltage jumper or high-voltage wire harness, low-voltage wire harness and relay. The high-voltage wiring harness can be regarded as the "arterial blood vessel" of the battery PACK, continuously delivering the power from the heart of the power battery system to the required components, while the low-voltage wiring harness can be regarded as the "neural network" of the battery PACK, transmitting detection and control signals in real time.
There are four main types of thermal management system: air cooling, water cooling, liquid cooling, phase change materials. Take water cooling system as an example, the heat management system mainly consists of cooling plate, cooling water pipe, heat insulation pad and heat conduction pad. The thermal management system is equivalent to installing an air conditioner in the battery PACK.
Some people may ask, why do batteries need a heat management system? In fact, the process of charging and discharging is a process of chemical reaction. The chemical reaction will release a lot of heat, which needs to be taken away to keep the battery in a reasonable operating temperature range to improve the battery life and reliability.
BMS: the Battery management system is the brain of the Battery. It is mainly composed of CMU and BMU.
CMU: Cell monitor unit is responsible for measuring battery voltage, current, temperature and other parameters, as well as balancing functions. When this data is measured by the CMU, it is transmitted to the BMU via the aforementioned battery "neural network".
BMU：Battery management Unit
It is responsible for evaluating the data transferred by CMU, protecting the battery if the data is abnormal, issuing a request to reduce the current, or cutting off the charging and discharging channels to avoid exceeding the permitted conditions of the battery, as well as managing the battery capacity and temperature. According to the control strategy previously designed, determine the parameters and status of the warning, and send the warning to the vehicle controller, and finally to the driver.
| Electric vehicle battery components | Cost (yuan) | proportion of cost |
| Li-ion battery cells | 11550 | 50% |
| Margin and warranty | 3003 | 13% |
| Battery management system(BMS) | 1848 | 8% |
| Pack overheads,depreciation and labour | 1617 | 7% |
| Power electronics | 1386 | 6% |
| Internal cell support | 1155 | 5% |
| Wiring,harnesses,connectors and interconnections | 1155 | 5% |
| Housing | 924 | 4% |
| Temperature control(forced air) | 462 | 2% |
| total cost | 23100 | 100% |
As the expansion of industrial scale and the improvement of technology, the overall cost of lithium battery continues to decline is the general trend. According to the data of recent ten years, the cost of lithium battery is also declining. With the intensification of industry competitiveness, lithium battery enterprises also began to focus on technology upgrading, research and development, production, sales of better quality products in line with future demand to supply the market and promote industrial technology upgrading.
The real price of lithium-ion batteries has fallen by 85% since 2010. This cost reduction is due to the economic benefits and the use of new high energy density anode materials of the scale production of lithium-ion batteries.
Based on the data collected, BloombergNEF calculates that lithium-ion battery manufacturing has a learning rate of 18%. This means that every time the cumulative production of lithium-ion batteries doubles, the price will fall by 18%.
At this rate, lithium-ion battery pack will cost less than $100 per kWh by 2024.
In order to bring the price down to the above level, the lithium ion battery industry must continue to use high energy density anode and cathode materials, and reduce the cost of battery raw materials. At the same time, new manufacturing technologies will save energy, raw materials and space.
lithium ion battery cost per kWh
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