Power lithium batteries are power sources that supply power to tools, primarily referring to batteries that power electric vehicles, electric trains, electric bicycles, and golf carts. They differ significantly from starter batteries used to start car engines. They commonly employ valve-sealed lead-acid batteries, open-type tubular lead-acid batteries, and lithium iron phosphate batteries.
A storage battery, a type of lithium-ion battery, stores limited electrical energy for later use. Its working principle is the conversion of chemical energy into electrical energy. It uses a lead plate filled with spongy lead as the negative electrode and a lead plate filled with lead dioxide as the positive electrode, with a 22-28% dilute sulfuric acid solution as the electrolyte. During charging, electrical energy is converted into chemical energy, and during discharging, chemical energy is converted back into electrical energy. During discharge, metallic lead, the negative electrode, undergoes oxidation to become lead sulfate; lead dioxide, the positive electrode, undergoes reduction to become lead sulfate again. When charged with direct current, lead and lead dioxide are generated at the two electrodes respectively. After the power source is removed, it returns to its pre-discharge state, forming a chemical battery. A storage battery is a rechargeable battery, called a secondary battery. Its voltage is 2V, and three storage batteries are usually connected in series to achieve 6V. Automobiles use six storage batteries connected in series to form a 12V battery pack.
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 conditions. Therefore, lithium-ion batteries were not widely used for a long time. However, with the development of microelectronics technology in the 20th century, the increasing miniaturization of devices placed higher demands on power supplies. Lithium-ion batteries subsequently entered a stage of large-scale practical application.
What is the relationship between power lithium batteries and lithium-ion batteries?
Batteries can be classified by chemical type into lead-acid batteries, primary alkaline batteries, nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and so on. They can also be classified by their discharge current into power lithium batteries and ordinary batteries. The basic difference between power lithium batteries and ordinary batteries is that ordinary batteries can discharge at a maximum current of 3C, while power lithium batteries generally refer to batteries that can discharge at a current of 5C, and ultra-high rate power lithium batteries can discharge at a current of 20C or higher.
Therefore, lithium-ion batteries come in both standard and power types. Power lithium batteries include lead-acid batteries, nickel-metal hydride batteries, and lithium-ion batteries, among others.
What are the differences between power lithium-ion batteries and consumer lithium-ion batteries from a research and development perspective?
For power-grade lithium-ion batteries, reliability and consistency are paramount, given their long-term use in harsh environments (low temperatures in winter, intense sunlight in summer, rain, and snow) and the need for large-scale series and parallel battery packs. Considering reliability and consistency, assuming a car uses 1000 power lithium-ion batteries, ideally, automakers want no problems even with a fleet of 100,000 vehicles of a particular model. This means the probability of a power lithium-ion battery failure should ideally be less than one in 100 million. To ensure reliability, power-grade batteries generally have greater design redundancy, using thicker separators, foils, and casings; therefore, their energy density is roughly half that of consumer batteries.
Consumer lithium-ion batteries do not require long-term reliability and are generally not used in pairs or individually, so consistency is not a major requirement. However, due to the limited space and high value of consumer mobile phones and tablets, consumer lithium-ion batteries have strict requirements on size, capacity, and energy density.
In terms of safety, power lithium batteries have more external protection circuits and heat dissipation layouts, and of course they also face harsher conditions (higher external voltage, greater current, and more complex external environment). Consumer batteries have less protection and rely on battery materials and design to withstand various safety-threatening situations based on higher energy density.
High-end consumer batteries use the most advanced technologies and materials, while power lithium batteries require more advanced process control, consistency control and quality management.
1. The capacities are different; mobile phones and other electronic products generally have larger capacities.
2. The cycle life of the power will also be higher.
3. In terms of temperature control, the power system has a protective temperature for the battery pack.
What are the differences between power lithium-ion batteries and capacity-type lithium-ion batteries?
There are many types of lithium-ion batteries, such as power lithium-ion batteries and capacity lithium-ion batteries. So what are the differences between these two types of lithium-ion batteries?
1. Different voltage levels
In the battery industry, an increase in voltage leads to an increase in the corresponding output voltage, enabling power lithium-ion battery packs to meet the needs of some high-power devices. The direct result of parallel connection is an increase in the current of the entire battery pack. Since capacity is affected by the output current, the direct purpose of parallel connection is to increase the capacity of lithium-ion battery packs. Battery packs connected in this way often have a larger capacity, which is the so-called capacity-type lithium-ion battery pack.
2. Different products are used.
Some large equipment requires higher voltage values because low-power battery packs cannot operate it, so high-capacity lithium-ion battery packs are used. For example, the electric bicycles we use every day often require a voltage of 48V, which is quite high for most everyday situations. Therefore, high-capacity lithium-ion battery packs are necessary to ensure the operation of electric bicycles. On the other hand, in large supermarkets or shopping malls, some sign lights and backup power supplies generally use high-capacity lithium-ion battery packs because their power consumption is not very high. These two types of equipment have different applications.
3. Different internal resistances
The internal resistance of power lithium-ion batteries is lower than that of capacity lithium-ion batteries. Taking 18650 batteries as an example, good manufacturers with 3x discharge rate batteries usually include PDC and have an internal resistance of around 40; batteries with 5x discharge rate batteries generally do not include PDC and have an internal resistance of around 20.
