Do you know what factors influence the price and safety of lithium-ion batteries? Lithium-ion battery energy storage is an inevitable trend in the development of the times. The application and development of lithium-ion batteries are very rapid, with advantages such as high energy density, long service life, and environmental friendliness. Recently, many people have asked me what factors affect the price and safety of lithium-ion battery packs. I kept them in suspense until now, and now I'll explain it in detail in this article, hoping it will be helpful to you.
Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as the negative electrode material and a non-aqueous electrolyte solution. Due to the highly reactive chemical properties of lithium metal, its processing, storage, and use require very strict environmental controls. Lithium batteries are widely used in the electric vehicle industry, and the emergence of lithium iron phosphate batteries has further propelled the development and application of the lithium-ion battery industry.
I. Price Composition of Lithium-ion Batteries
The price of lithium-ion batteries is mainly composed of three major components: the battery cell, the protection board, and the casing. At the same time, the choice of materials for the connecting pieces between the battery cells will affect the cost due to the power consumption and current of the electrical appliances being used. Different connectors may also have a significant impact on the cost. In addition, different PACK processes will also affect the cost.
II. Factors Affecting the Price of Lithium-ion Batteries
① Selection of battery cells:
The selection of cells based on different material systems affects the overall price of lithium-ion batteries. Lithium-ion battery packs use various cell systems depending on the cathode material, such as lithium manganese oxide (3.6V), lithium cobalt oxide (3.7V/3.8V), lithium nickel cobalt manganese oxide (commonly known as ternary, 3.6V), lithium iron phosphate (3.2V), and lithium titanate (2.3V/2.4V). Cells based on different material systems have different voltage platforms, safety factors, cycle life, energy density ratios, and operating temperatures.
The prices of battery cells from different brands can vary greatly. The general price gradient can be divided into: battery cells with the same material system but different brands can have very different prices. Moreover, the quality (safety, consistency, stability) of battery cells from different brands that have survived the market competition is basically proportional to the price.
② Requirements and design of lithium-ion battery PCM
PCM design can be divided into: basic protection, communication, and BMS.
Basic protection: Basic protection includes overcharge, over-discharge, overcurrent and short circuit protection, and over-temperature protection can be added according to product requirements.
Communication: Communication protocols can be divided into I2C, RS485, RS232, CANBUS, HDQ, SMBUS, etc. There is also a simple power display, which can be achieved by using a power meter with LED indicators.
BMS (Battery Management System) is primarily designed for the intelligent management and maintenance of individual battery cells, preventing overcharging and over-discharging, extending battery life, and monitoring battery status. Its key functions include: real-time monitoring of battery physical parameters; battery status estimation; online diagnostics and early warning; charge, discharge, and pre-charge control; equalization management; and thermal management.
③ Requirements and design of lithium-ion battery casings
Lithium-ion battery casing designs can be categorized into: PVC heat-sealed, plastic, and metal.
PVC heat sealing: The specific casing method used for the battery pack depends on the customer's product requirements. PVC heat sealing is generally suitable for cases where the number of cells in series and parallel is small and the overall weight is relatively light (≤2kg). However, for battery packs with an overall weight ≥1kg, fixing brackets should be added between the cells, and a fiberglass plate should be added for external protection before using PVC heat sealing.
Plastic: Plastic casing is used because after different battery packs are finalized, the casing may need to be molded, and the mold cost is a considerable expense. In the early stages of development, before the product is finalized, a prototype casing can be made. Different requirements for the casing material and process will also affect the cost.
Metal: Similar to plastic casings, for metal casings, sheet metal prototyping is recommended before the product is finalized or for small quantities. This is important because it results in a shorter lead time. For larger batches, mold making is also recommended. Waterproofing requirements for metal casings will significantly impact costs, and special materials for metal casings will also increase costs.
In summary, the cost of lithium-ion batteries mainly consists of the cell, PCM (Polymer Processing Unit), and structural components, plus the company's PACK (packaging) costs, aging costs, and management costs. Furthermore, due to differences in product technical complexity, procurement volume, and defect rate requirements, the price of lithium-ion batteries can vary significantly!
III. Factors Affecting the Safety of Lithium-ion Batteries
1. The ambient temperature should not be too high or too low; it is best to operate at normal temperature.
2. A violent impact or puncture will immediately cause it to catch fire;
3. Over-discharge significantly reduces the lifespan of lithium-ion batteries;
4. Poor circuit insulation leading to water ingress and causing short circuits, etc.
After saying all that, I've decided to give you another bonus: how to choose a lithium-ion battery pack.
IV. Several points to note when purchasing lithium-ion batteries:
▲Is the capacity clearly marked? Batteries without a clearly marked capacity are very likely to be made from inferior or recycled batteries. Many cheap batteries on the market are made from recycled battery cells. Although they are cheap, they have a short lifespan, unstable quality, and may damage your phone if used carelessly.
▲Is there a guarantee on standby time? Standby time refers to the continuous usage time from when the battery is inserted into the phone until the next charge. Generally, batteries sold on the market cannot guarantee standby time to customers. This is because the quality of batteries is unstable. Many cheap batteries use poor-quality battery cells, so their standby time is very short.
▲Whether a safety protection circuit board is installed. Without a protection circuit board, lithium-ion batteries are at risk of deformation, leakage, and explosion. In the face of fierce price competition, manufacturers seek even lower-priced protection circuit boards, or simply omit this device altogether, resulting in a market flooded with lithium-ion batteries that pose an explosion hazard. Consumers cannot visually determine whether a protection circuit board is present; therefore, it is best to purchase from reputable vendors.
That concludes my overview of the factors influencing the price and safety performance of lithium-ion batteries. This summary is quite comprehensive. If you found it helpful, please share this article with your friends and colleagues!
Our company is a power supply company dedicated to the research and development and application of lithium-ion battery UPS. As a power supply supplier using lithium-ion batteries as energy storage, our products are widely used in: communications, power, public security, finance, network, medical, security, industrial automation, rail transportation, aerospace and marine fields.
