A Very Detailed Introduction of Lithium Battery Knowledge，hope it is useful to you. And if you want to know more, welcome to leave a comment.

Contents：

1. What are lithium batteries？

• What is the difference between a lithium battery and a lithium-ion battery?

2. Applicationsand Service life of lithium battery

(1) What are lithium batteries used for?

(2) How long does the lithium battery last?

(3) Which battery has longest life?

3. Safety of lithium batteries

1. What are the dangers of a lithium battery?
2. Why can’t bring lithium batteries on a plane?
3. Why do lithium batteries explode and how to prevent lithium battery explosion?

4. Why lithium battery is expensiveand the factors affecting the price of lithium battery?

5. How to buy lithium batteries?

1. What are lithium batteries？

Lithium battery is a kind of battery with lithium metal or lithium alloy as positive/negative material and non-aqueous electrolyte solution. Lithium metal battery was first proposed and studied by Gilbert N. Lewis in 1912. In the 1970s, M. S. Whittingham proposed and began to research lithium-ion batteries. Due to the chemical characteristics of lithium metal is very active, the processing, preservation and use of lithium metal have very high environmental requirements. With the development of science and technology, lithium battery has become the mainstream.

Lithium batteries can be roughly divided into two categories: lithium metal batteries and lithium-ion batteries. Lithium-ion batteries do not contain metallic lithium and can be recharged. Lithium metal battery, the fifth generation of rechargeable battery, was born in 1996. Its safety, specific capacity, self-discharge rate and performance-to-price ratio are better than lithium-ion battery. The lithium-metal battery is being produced by companies in only a handful of countries because of its high technical requirements.

What is the difference between a lithium battery and a lithium-ion battery?

Strictly speaking, lithium batteries are lithium-dithionyl chloride batteries, which are primary batteries, that can only discharge cannot charge, and can only be recycled when they are used up. Lithium-ion battery is what we usually use, belongs to the secondary battery, can be repeatedly recharged and used. Lithium-dithionyl chloride batteries are no longer in use, people for the sake of simplicity to lithium-ion batteries referred to as lithium batteries, so in the current context, the two are actually the same thing.

2. Applicationsand Service life of lithium battery

(1) Whatarelithium batteries used for?

With the development of lithium battery technology, many fields have put forward high requirements for power supply. Lithium batteries have also entered into a large-scale practical stage.

At present, lithium batteries are mainly used in electric cars, electric bicycles, electric motorcycles, medical, security, solar energy storage batteries, RVs, yachts, golf carts, sweepers, fishing tackle and UPS power supply, etc.

(2) How long does the lithium battery last?

The life cycle range of Li-ion batteries can vary widely, but the general range is 500 to 1500 cycles. A cycle is defined as charging the battery once. The exact number of cycles depends on a variety of factors, including:

A. The depth of discharge and the number of rechargeable cycles, the number of rechargeable cycles * depth of discharge = the total number of charge cycles completed, the higher the total number of charge cycles completed, the higher the life of the battery, i.e. the number of rechargeable cycles * depth of discharge = the actual battery life (ignoring other factors)

B. Overcharge, over-discharge, and large charging and discharging currents to avoid overcharging the battery, any form of overcharging of lithium-ion batteries can lead to serious damage to the battery performance, or even explosion.

C. Too hot or too cold environment, temperature also has a greater impact on the life of lithium batteries. Below freezing environment is likely to make the lithium battery in the moment of opening electronic products burned, while too hot environment will shrink the capacity of the battery.

Effect of temperature and initial charge on lithium battery storage

D. Long time full charge, no charge state.

(3) Which battery has longest life?

At present, the widely used batteries are mainly ternary lithium battery and lithium iron phosphate battery. The former can meet the basic requirements in terms of battery life, but the performance in terms of battery life is not satisfactory.

As for the Lifepo4 battery, its service life is longer, but its performance in the aspect of battery life is far behind that of ternary lithium battery.

In response to this problem, and in order to meet the higher requirements of customers for batteries, SmarTEC has focused on improving the quality and service life of lithium batteries for over 15 years.

3. Safety of lithium batteries

(1) What are the dangers of a lithium battery?

(2) Why can’t bring lithium batteries on a plane?

Why can lithium batteries be transported by air, but on passenger planes, you cannot check in lithium batteries or electronic products with lithium batteries?

Airline regulations: passengers who carry electronic products with lithium batteries, then will not be allowed to follow the baggage together with the check-in, but passengers can carry electronic products with lithium batteries in hand luggage, such as cell phones, cameras, laptops, etc., and each person can only carry no more than 2 pieces of spare batteries, and to make measures to prevent the battery short circuit. In other words, in passenger aircraft, is not allowed to check in lithium batteries or electronic products with lithium batteries.

But if it is all-cargo air freighter, the restrictions will be much wider. Because when it is all-cargo air freighter, the goods will be strictly sorted and loaded, so that the danger can be reduced; unlike passenger planes where many different cargoes are piled up together, if the cargo is entrained with dangerous goods for air transport, the danger is greatly increased. Therefore, lithium batteries can be transported by all-cargo aircraft.

(3) Why do lithium batteries explode and how to prevent lithium battery explosion?

A:Why do lithium batteries explode?

1). Thermal runaway leads to spontaneous combustion of lithium batteries, which means that the battery itself overheats, or charging in a high-temperature environment leads to spontaneous combustion and explosion phenomenon.

2). Lithium battery packaging damage, lithium batteries have a layer of internal diaphragm, in the case of heavy trauma or sharp objects pierced, the diaphragm will be damaged, resulting in lithium battery internal short circuit, will also lead to lithium battery spontaneous combustion and explosion.

3). If the voltage and current of the lithium battery exceeds the specified value (such as the 20-ampere lithium battery using a 30-ampere charger) will lead to high temperature of the lithium battery, which is also easy to cause the lithium battery explosion and fire.

4). The quality of lithium batteries, there are a few manufacturers to save costs and cut corners, use waste lead as raw materials refit to make lithium battery, such lithium batteries without quality assurance and brand certification, the production of batteries are also prone to “leakage” phenomenon, which leads to lithium batteries spontaneous combustion and explosion.

B: How to prevent lithium battery explosion?

• • choose the lithium battery from regular manufacturers, please do not choose the battery which no label and no warranty.
  • use the original charger for lithium batteries, the general lithium battery will match the qualified charger, do not take too long to charge, unplug the charger in time after a full charge.
  • to avoid heavy damage to the battery.
  • Charge the battery after the heat is dissipated, the battery is still in a heat dissipation state after use, this time is not suitable for charging. The heat of the battery itself plus the heat of the charger into the current, will allow the battery to be heated sharply inside, resulting in the loss of battery water, once encountered in a high-temperature environment, it will occur naturally. Try to place the battery to cool completely before charging, and choose a cool and ventilated place

• do not recklessly charge after wet or flooding, it is best not to recklessly charge in a wet environment or after accidentally entering the water.

4. Why lithium battery is expensiveand the factors affecting the price of lithium battery?

Lithium battery is mainly composed of three parts: cells, protective board and shell. Different connectors (such as aviation plug, the price ranges from a few dollars to hundreds of dollars) may also have a great impact on the cost, and different PACK processes will also affect the cost.

(1) The selection of cell with different material system will affect the price of lithium battery.  Lithium battery according to the different cathode materials, there will be a variety of material systems such as lithium manganate cells, different material systems, the voltage platform, safety factor, the number of cycles, energy density ratio, working temperature, etc. are not the same.

(2) The price of the cells of different brands also can differ very big, the same material system and different brands of battery cells, the price difference will also be very large, and through the market out of the quality of each brand of battery cells (safety, consistency, stability) is basically proportional to the price.

(3) Protection board including PCM and BMS, PCM design can be divided into: basic protection, communication, BMS basic protection: basic protection including overcharge, overdischarge, overcurrent and short circuit protection, and can be added over temperature protection according to product requirements. Communication protocol can be divided into I2C, RS485, RS232, CANBUS, HDQ, SMBUS, etc.

(4) Lithium battery shell requirements and lithium battery shell design can be divided into: PVC heat seal, plastic, metal PVC heat seal. What kind of shell packaging form is used outside the battery pack, mainly depends on the customer’s specific needs for the product. For the packaging form of PVC heat sealing, it is generally applicable to the case that the battery string is not many and the overall weight is light (≤2kg). However, for the overall weight of the battery pack ≥1kg, it is necessary to add a fixed bracket between the cell, add glass fiber board protection on the periphery, and then use PVC heat sealing.

5. How to buy lithium batteries?

Lithium batteries are divided into lithium-ion batteries and lithium polymer batteries. Lithium-ion batteries have a fluid electrolyte, while Li-polymer batteries have a solid electrolyte, so they are more unstable than Li-polymer batteries. If you buy a poor quality lithium battery, it is like putting a “time bomb” around you. Therefore, consumers must pay attention to the following 3 points when purchasing lithium batteries.

1. Whether the capacity is clearly marked. Lithium batteries without clearly marked capacity are likely to be junk batteries with poor quality cells or recycled cells. Many cheap lithium batteries on the market are made from recycled or dismantled battery cells, which are cheap but have a short life span and unstable quality, and may damage the device or even explode if used carelessly.

2. The factory test report. Qualified and good quality battery packs are often required to go through multiple layers of testing before leaving the factory. After the battery pack has a clearly marked capacity, and then with the test report, which is more real and reliable.

3. Whether with safety protection board(BMS). The characteristics of lithium batteries determine the lithium battery must be added to the protection board to prevent the lithium battery overcharge, over discharge and short circuit, etc., without the protection board of the lithium battery will have deformation, leakage, the risk of explosion. In the face of fierce price competition, battery manufacturers seek lower cost protection circuits or omit this device, making the market flooded with lithium batteries that are at risk of explosion. Consumers cannot tell from the appearance whether there is a protective circuit board or not, so it is best to choose a reputable merchant to buy from.