Prismatic battery vs Cylindrical battery, What is the difference?

Prismatic lithium batteries usually refer to aluminum or steel case prismatic batteries, the popularity of prismatic batteries is very high in China, so what are the differences between them? Prismatic battery vs Cylindrical battery

Cylindrical lithium batteries are divided into lithium iron phosphate, lithium cobaltate, lithium manganese, and cobalt-manganese hybrid, ternary materials of different systems, the shell is divided into two kinds of steel shell and polymer, different material system batteries have different advantages. At present, cylindrical mainly steel shell cylindrical lithium iron phosphate batteries, the performance of this battery is high capacity, high output voltage, good charging and discharging cycle performance, stable output voltage, capable of high-current discharge, electrochemical stability, safe to use, wide operating temperature range, friendly to the environment, widely used in solar energy lamps and lanterns, lawn lamps and lanterns, back-up energy, power tools, toys and models.

What is the difference between Prismatic battery vs Cylindrical battery?

1. Battery shape: prismatic size can be designed arbitrarily, while cylindrical batteries can not.
2. Multiplier characteristics: Cylindrical batteries are limited by the process of welding multi-electrode lugs, the multiplier characteristics are slightly worse than prismatic multi-electrode batteries.
3. Discharge platform: using the same positive and negative materials and electrolyte lithium batteries, theoretically speaking, the discharge platform should be the same, but the prismatic lithium batteries within the discharge platform are slightly higher.
4. Product quality: Cylindrical battery manufacturing process is more mature, the pole piece has a low chance of secondary slitting defects, and the maturity of the winding process and the degree of automation is relatively high, the iterative process is still using a semi-manual way, which has a negative impact on the quality of the battery.
5. Lug welding: cylindrical battery lugs are easier to weld than prismatic lithium batteries; prismatic lithium batteries are prone to false welding affecting battery quality.
6. PACK process: cylindrical batteries have more easy-to-use features, so the PACK technology is simple, good heat dissipation; prismatic lithium battery PACK to solve the problem of heat dissipation.
7. Structural characteristics: the corners of the prismatic lithium battery chemical activity is poor, long-term use of the battery energy density is easy to decline, shorter range.

With the rise of automotive power batteries in recent years, automotive range and battery capacity of contradiction between the increasingly prominent, power lithium ion battery manufacturers more than the use of higher energy density of the battery aluminum shell prismatic battery-based, because the structure of the prismatic battery is relatively simple, unlike cylindrical batteries using high strength stainless steel as a shell and with explosion-proof safety valves, and other accessories, so the overall accessory weight to be lighter, relative energy density is higher.

What are the Advantages and Disadvantages of Prismatic battery vs Cylindrical battery?

Analysis of Cylindrical lithium-ion battery

Earlier cylindrical lithium-ion batteries is created by the Japanese SONY company in 1992 18650 lithium batteries, 18650 cylindrical lithium-ion batteries because of the long history of the battery, so the whole market has a high ownership rate, cylindrical lithium-ion batteries using a mature and perfect winding process production process, the degree of automation is high, the product passes through the quality of the stability of the total cost of a relatively low.

Cylindrical lithium-ion batteries have many models, such as the common 17490, 14650, 18650, 26650, 21700 and so on. Cylindrical lithium-ion batteries in Japan, South Korea’s lithium-ion battery companies are more predominantly, China, our country also has a considerable scale of enterprises in the production of cylindrical lithium-ion batteries.

With the high-speed development of the whole market of electric vehicles in our country, vehicle manufacturers have put forward higher requirements for power batteries in terms of energy density, manufacturing cost, product value-added, and cycle life. In the raw material field has not yet obtained a huge breakthrough in the premise, the appropriate increase in the size of the cylindrical battery to obtain more battery capacity has become a kind of explorable direction.

At this stage, Tesla has already started the large-scale production of 21700 batteries, and plans to use them mainly in Tesla’s Model 3, and as long as they are tested in other Tesla’s models, all of them will be replaced by 18650 batteries, which will lead a wave of “21700 Trend” in the world.

Analysis of prismatic lithium-ion battery

prismatic lithium-ion battery usually refers to the aluminum or steel casing prismatic battery, prismatic battery ownership rate in our country is very high, our country’s power battery manufacturers mostly use the battery with higher energy density of the aluminum casing prismatic batteries, because the prismatic battery structure is relatively simple, unlike cylindrical batteries using high strength stainless steel as a shell and with explosion-proof safety valve and other accessories, so the overall weight of the accessories to be lighter compared to the Higher energy density. prismatic batteries have a variety of processing and production processes using two kinds of stacked and coiled.

However, because prismatic lithium-ion batteries can be customized according to the size of the product, there are thousands of styles on the market, and because there are so many styles, it is extremely difficult to standardize the production process. prismatic batteries in ordinary electronic appliances is no problem, but relative to industrial equipment products that want more than one series, parallel connection, it is best to choose standardized production of cylindrical lithium-ion batteries, so that the production process is guaranteed, and it is easier to find replaceable batteries in the future.

However, because prismatic lithium-ion batteries can be customized according to the size of the product, there are thousands of styles on the market, and because there are so many styles, it is extremely difficult to standardize the production process. prismatic batteries in ordinary electronic appliances is no problem, but relative to industrial equipment products that want more than one series, parallel connection, it is best to choose standardized production of cylindrical lithium-ion batteries, so that the production process is guaranteed, and it is easier to find replaceable batteries in the future.

Difference between the technical characteristics, Prismatic battery vs Cylindrical battery

1. Multiplier characteristics level: cylindrical lithium battery welding multi-ear technology is limited, so the multiplier characteristics are slightly weaker than the prismatic multi-ear scheme.
2. Battery style level: prismatic lithium batteries can adjust the size at will, so the cylinder battery can not be compared.
3. Product quality: cylindrical lithium battery technology is very mature, the pole piece of the public has a low probability of secondary division defects, and winding technology than the stacked technology maturity and the level of automation technology is higher than the stacked technology at this stage is still used in the selection of semi-handmade, so the quality of the battery has a negative impact.
4. Discharge platform level: the same cathode material, anode material and electrolyte are used, so theoretically the discharge platform is the same, but the internal resistance of the prismatic battery is slightly dominant, so the discharge platform is a little higher.
5. Structural characteristics: the chemical energy at the corners of the prismatic battery is weak, and the performance of the battery decreases significantly after a long time of use.
6. PACK formation level: Cylindrical batteries are relatively easy to operate characteristics, so the PACK program is simple, the heat dissipation effect is very good, and prismatic battery packs need to deal with the problem of heat dissipation.
7. Lug welding level: cylindrical lithium battery lugs are easier to weld than prismatic lithium batteries, prismatic batteries are prone to welding affecting the quality of the battery.

In sum, whether cylindrical, prismatic or soft pack batteries, the reason why they can all develop rapidly at this stage is because they are well used in their respective application areas in which they excel. Domestic power battery manufacturers are predicting that the prismatic type will become the mainstream of the power battery, but Tesla as the representative of the cylinder power battery application manufacturers, continuous innovation in technology, the whole vehicle battery energy density continues to improve, the battery performance to express more excellent.