Four key materials for lipo battery 3s dry goods!

How does lipo battery 3s generate electricity?

When the lipo battery 3s is working, lithium ions participate in the redox reaction to convert chemical energy into electrical energy, which is why the lipo battery 3s can provide electrical energy. The evaluation indicators of a lipo battery 3s product include energy density, cycle life, rate performance (discharge performance under different currents), safety performance, and applicable temperature.

Cost composition of lipo battery 3s

From the perspective of the cost structure of lipo battery 3s, the positive electrode, negative electrode, electrolyte and separator are the four key raw materials, and their proportion in the cost is much higher than that of other materials such as wire harnesses, connectors and conductive agents. This is similar to lipo battery 3s. The basic working principle is the same.

Four key materials of lipo battery 3s

1. lipo battery 3s positive electrode material

At present, the positive electrode material is the core material of the lipo battery 3s, which is a key factor determining the performance of the battery. It has a direct impact on the final energy density, voltage, service life and safety of the product. It is also the most expensive part of the lipo battery 3s. For this reason, lipo battery 3s is often named after the positive electrode material, such as the ternary battery, which is the lipo battery 3s that uses the ternary material as the positive electrode.
The energy density of lipo battery 3s refers to the electric energy that can be released by the average unit volume or mass of the battery. The higher the energy density, the higher the mileage of the battery. This indicator is one of the important basis for whether a lipo battery 3s can enjoy government subsidies.
About the energy density of lipo battery The following article introduces the method of improving the energy density of lipo battery in detail. Interested partners can click to view:
1200mah lipo battry energy density improvement - cell density improvement

The difference between different cathode materials is obvious, and the application fields are also different. Common cathode materials can be divided into lithium cobalt oxide (LCO), lithium manganate (LMO), lithium iron phosphate (LFP), and ternary materials (NCM).
1) Lithium iron oxide material
Lithium cobalt oxide is the earliest commercialized cathode material. Its energy density is higher than that of rechargeable batteries such as nickel-metal hydride and lead-acid. It first reflects the development potential of lipo battery 3s, but it is very expensive and has a low cycle life. It is only suitable for 3C electronic products. . Although lithium manganate has a low cost, its energy density is not good. It was used in the early slow-speed electric vehicles, such as battery cars, to a certain extent. Today, it is mainly used in power tools and energy storage fields, and is rarely seen in power batteries.
2) Ternary material
The core advantage of ternary materials is their high energy density. Under the same volume and quality, the battery life is far ahead of other technical routes. But its defects are also very obvious: poor safety, low ignition point when subjected to shock and high temperature environment. In recent safety tests such as acupuncture and overcharge, which are hotter, it is difficult for large-capacity power ternary batteries to pass the test. It is the defect in safety performance that has always limited the large-scale assembly and integrated application of the ternary material technology route.

Lithium iron phosphate is just the opposite of ternary materials, with average energy density and battery life, but excellent safety.
In addition to the safety advantage, another major factor behind the rapid rise in sales of lithium iron phosphate is cheapness. For a long time, the main reason for the high cost of raw materials for ternary batteries (accounting for nearly 90%) is the large demand for cobalt. Cobalt is a rare mineral. It is very expensive and extremely unstable to mine. The price fluctuates wildly. The supply chain is also very fragile, which can easily affect downstream industries.
The battery life of a typical lithium iron phosphate electric vehicle is about 300~400km, which is enough to meet the needs of urban traffic. The ternary battery cannot reflect its core advantages in this application scenario.
Driven by the dual drive of cost and infrastructure, it is not surprising that more and more car companies choose the lithium iron phosphate technology route. Even the power battery giant CATL, which started with ternary batteries, is rapidly increasing the production capacity of iron phosphate lipo battery 3s and supplying iron phosphate lipo battery 3s for the standard battery life version of the domestic Tesla Model 3.

However, the development of ternary batteries has not stopped. The long-term trend of this technical route is to reduce costs through the ratio of high nickel and low cobalt, the so-called high nickel ternary material.
This article about lipo battery cathode material has a more detailed introduction. Interested partners can click to view:
Detailed explanation of 6s lipo battery cathode material

2. Lipo battery 3s negative electrode material

The negative electrode material of lipo battery 3s is made of active substances, binders and additives into a paste-like adhesive, and then smeared on both sides of the copper foil, dried and rolled, to store and release energy, which mainly affects the cycle of lipo battery 3s performance indicators.
According to the active materials used, the negative electrode materials can be divided into two categories: carbon materials and non-carbon materials:
1) Carbon-based materials
Carbon-based materials include two routes: graphite materials (natural graphite, artificial graphite, and mesophase carbon spheres) and other carbon-based materials (hard carbon, soft carbon, and graphene);
2) Non-carbon materials
Non-carbon-based materials can be subdivided into titanium-based materials, silicon-based materials, tin-based materials, nitrides, and metallic lithium.
Different from the positive electrode material, although the negative electrode of the lipo battery 3s has the same number of routes, the final product is very simple, and artificial graphite is the absolute mainstream. Data shows that China's artificial graphite shipments in 2020 will be about 307,000 tons, accounting for 84% of the total shipments of anode materials, a further increase of 5.5 percentage points from the 2019 level.

Compared with other materials, artificial graphite has good cycle performance, superior safety, mature technology, easy access to raw materials, and low cost. It is an ideal choice.
3) A new generation of anode materials
The core problem of graphite negative electrode is that the theoretical upper limit of the energy density of graphite negative electrode material is 372mAh/g, while the products of leading companies in the industry can already achieve an energy density of 365mAh/g, which is close to the theoretical limit, and the future improvement space is extremely limited. There is an urgent need to find next-generation alternatives.
Among the new generation of anode materials, silicon-based anodes are popular candidates. It has a very high energy density, and the theoretical capacity ratio can reach 4200mAh/g, far exceeding that of graphite materials. However, as a negative electrode material, silicon also has serious defects, and the intercalation of lithium ions will cause severe volume expansion, damage the battery structure, and cause a rapid decrease in battery capacity.

One of the current solutions is to use silicon-carbon composite materials. Silicon particles are used as the active material to provide lithium storage capacity. The particles agglomerated during charge-discharge cycles.
Based on this, silicon carbon anode materials are considered to be the most promising technical route, and gradually gain the attention of enterprises in the industry chain. Tesla's Model 3 has used an artificial graphite anode battery doped with 10% silicon-based material, and its energy density has successfully achieved 300wh/kg, which is significantly ahead of batteries using traditional technical routes.

However, compared with graphite anodes, in addition to the immature processing technology of silicon carbon anodes, the higher cost is also an obstacle. The current market price of silicon carbon anode materials exceeds 150,000 yuan/ton, which is twice that of high-end artificial graphite anode materials. After mass production in the future, battery manufacturers will also face similar cost control issues as cathode materials.

3. lipo battery 3s electrolyte

In the lipo battery 3s, the electrolyte is mainly used as a carrier for ion migration to ensure the transmission of ions between the positive and negative electrodes. Its safety of lipo battery 3s (about the safety problems of lipo battery, this article introduces preventive measures to deal with the safety problems of lipo battery, and the partners who need it can read it by themselves: cnhl 6s lipo battery safety problems and preventive measures), cycle life, charge and discharge rate, high and low temperature performance, energy density and other performance indicators have certain influences.

The electrolyte is generally made up of raw materials such as high-purity organic solvent, electrolyte lithium salt and additives in a certain proportion. According to the quality, the solvent quality accounts for 80%~90%, the lithium salt accounts for 10%~15%, and the additive accounts for about 5%; according to the cost, the lithium salt accounts for about 40%~50%, and the solvent accounts for about 40%~50%. About 30%, and additives account for about 10% to 30%.
1) Requirements for the electrolyte of lipo battery 3s
Compared with the other three materials, lipo battery 3s has the most complex requirements for electrolyte and needs to have various characteristics:
Good ionic conductivity and low ion migration resistance;
High chemical stability, no harmful side reactions with electrode materials, electrolytes, diaphragms, etc.;
The melting point is low, the boiling point is high, and it remains liquid in a wide temperature range;
The invention has the advantages of good safety, uncomplicated preparation process, low cost, non-toxic and non-polluting.
2) Mainstream lipo battery 3s electrolyte
Lithium Hexafluorophosphate
At present, lithium hexafluorophosphate (LiPF6) is the mainstream lithium salt solute due to its better performance and lower cost. It has good solubility and high electrical conductivity in various non-aqueous solvents, relatively stable chemical properties, good safety, and less environmental pollution. However, the defects are also obvious: lithium hexafluorophosphate is sensitive to moisture and has poor thermal stability. It may start to decompose at the lowest 60 °C, and the battery performance will decay rapidly. The cycle effect in low temperature environment is relatively general, and the adaptable temperature range is narrow.

In addition, lithium hexafluorophosphate has very high requirements on its purity and stability. The production process involves harsh working conditions such as low temperature, strong corrosion, no water and dust, and the production is also relatively difficult.
Lithium Bisfluorosulfonimide
Among the new generation of lithium salts, lithium bisfluorosulfonimide (LiFSI) is considered to be a promising alternative to lithium hexafluorophosphate. Compared with traditional lithium salts, LiFSI has higher thermal stability, and has advantages in electrical conductivity, cycle life, low temperature performance, etc.
However, limited by the production process and capacity, the cost of LiFSI is too high, far exceeding that of lithium hexafluorophosphate. In order to control the cost, LiFSI is still more used as an electrolyte additive in actual commercial use, rather than a lithium salt solute.
The detailed introduction of the lipo battery electrolyte is introduced in the following article, and the partners who need it can expand the reading:
Cnhl 6s lipo battery electrolyte, practical function and classic system construction

4. lipo battery 3s diaphragm

The lipo battery 3s separator is a thin film between the positive and negative electrodes, which can be used to separate the positive and negative electrodes to prevent short circuits when the lipo battery 3s undergoes an electrolysis reaction. The separator is immersed in the electrolyte, and there are a large number of micropores on the surface that allow lithium ions to pass through. The material, number and thickness of the micropores will affect the speed of lithium ions passing through the separator, which in turn affects the discharge rate, cycle life and other indicators of the battery.

Polyolefin is the current general lipo battery 3s separator material, which can provide good mechanical and chemical stability for lipo battery 3s separator. It is further subdivided into three categories: polyethylene (PE), polypropylene (PP), and composite materials. .
4.1lipo battery 3s diaphragm material selection
The choice of diaphragm material is related to the positive electrode material. At present, polyethylene is mainly used in ternary lipo battery 3s, and polypropylene is mainly used in iron phosphate lipo battery 3s.
In addition to the material, the preparation process also has a certain influence on the performance of the separator.
4.2 Production technology of lipo battery 3s diaphragm
The current production technology of lipo battery 3s separator is divided into two categories: dry method and wet method.
4.2.1lipo battery 3s diaphragm dry process
Dry method, also known as melt stretching method (MSCS), can be further subdivided into uniaxial stretching and biaxial stretching. This technical route has a long development time and is more mature, and is mainly used for the production of PP membranes. In addition, the biaxial stretching process is only used for low-end batteries due to poor finished product performance, and is no longer the mainstream preparation process.
The dry process has the characteristics of simplicity, low cost, and environmental friendliness, but the product performance is poor, and it is more suitable for low-power, low-capacity batteries. As mentioned above, the iron phosphate lipo battery 3s just has the defect of low energy density, so the separator using the dry process is mostly used in this technical route.

4.2.2lipo battery 3s diaphragm wet process
The wet process, also known as thermally induced phase separation (TIPS), differs from the dry process in which only the base film is stretched. The wet process coats the surface of the base film to improve the thermal stability of the material. Compared with products prepared by dry process, the diaphragm of wet process has obvious advantages in performance. Its thickness is thinner, its tensile strength is more ideal, its porosity is higher, it has more uniform pore size and higher transverse shrinkage. Rate. In addition, the puncture strength of the wet separator is higher, which is more conducive to prolonging battery life, and is more suitable for the development direction of lipo battery 3s with high energy density. It is currently mainly used in ternary batteries.
However, compared with the dry process, the wet process is relatively complex, expensive, and easily polluted to the environment.
4.3lipo battery 3s diaphragm wet process is rapidly replacing dry process
The current major market trends for diaphragm materials are well established. Because it is more in line with the requirements of high energy density of power batteries, it can prolong the cycle life of the battery, and can increase the high-rate discharge capacity of the battery. The wet process is rapidly replacing the dry process. The data shows that in 2017, the market share of wet-process lipo battery 3s separator exceeded that of dry-process separator for the first time, and in 2018 just one year later, the market share further rose to 65%.
The above is the whole content of the four key materials of lipo battery 3s brought to you by CNHL. I believe that after reading the whole text, everyone understands that the main parts of the cost of lipo battery 3s are the positive electrode material, negative electrode material, electrolyte and lipo battery 3s. battery 3s diaphragm. Hope the above content is helpful to you, if you need to buy lipo battery 3s, you can enter our online store: Chinahobbyline to buy, we have warehouses all over the world, you can buy with confidence; if you If you want to get more information about lipo battery, please click below:
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