Blade battery and CTP method to drive iron phosphate

　　Author ：Iflowpower – Portable Power Station Supplier

1, the lithium iron phosphate ion battery has cost and safety advantage 1.1LFP with its low price and strong safety in numerous positive electrode materials, the positive electrode material in the lithium-ion battery accounts for more than 40% of the entire battery cost, and under current technical conditions The energy density of the overall battery is important to the positive material, so the positive electrode material is the core development of a lithium ion battery. The material of the currently mature application includes lithium cobalt organte, lithium nickel-cobalt-manganese acid, lithium iron phosphate and manganese acid.

lithium. (1) Lithium cobaltate: there is a layered structure and a spinel structure, generally a layered structure, with a theoretical capacity of 270 mAh / g, and lithium layered structure is important for mobile phone, model, vehicle model, electronic smoke, Smart wear digital products. In the 1990s, Sony first used lithium cobaltate production of the first commercial lithium-ion battery.

my country's cobalt-cobalt-cobalt-acid products are basically monopolized by foreign manufacturers such as Japan, Rice Chemical, Qingmei Chemistry, Belgium 5,000. When the promotion in 2003, the promotion of the first domestic cobaltate in 2003 was launched in 2005, and in 2009, it achieved exporting South Korea and Japan. In 2010, it became the first company in China to log in to the capital market for the main business.

In 2012, Peking University first, Tianjin Bamo launched the first generation 4.35V high voltage cobaltate product. In 2017, Hunan Shanno, Xiamen Tungsten Industry launched 4.

45V high-voltage sowered lithium. The energy density and compaction density of lithium cobaltate have basically until the limit, and the specific capacity is compared with the theoretical capacity, but due to the current overall chemical system limit, especially the electrolyte in high voltage system. It is easy to decompose, so it is further limited by lifting a method of lifting the charging cutoff voltage increase, and the energy density will increase the space once the electrolyte technology is broken.

(2) Lithium nickellate: generally has green environmental protection, low cost (cost is only 2/3 of lithium cobaltate), good safety (safe working temperature can reach 170 ° C), long life (extend 45 %)The advantages. In 2006, Shenzhen Tianjiao, Ningbo Jin and took the lead in launching the three-way materials of the 333, 442, 523 system. From 2007 to 2008, the price of cobalt metal cobalt has increased significantly, leading to the spread of lithium cobaltate and lithium nickel-cobalt-mandanate material, promoting the application of lithium-commercial market in my country, and serve the first one.

Breakout period. In 2007, Guizhou Zhenhua launched a single crystal type 523 system of lithium nickellate material. In 2012, Xiamen Tungsten Export Japan Market.

In 2015, government subsidy policy guides the lithium nickel-watery-mlassical material ushered in the second outbreak period. Currently, the lithium monocytonide-cobalt-manganese acid is important to improve the energy density of the product, which improve the energy density of the product, but this to the electrolyte related supporting materials and lithium-ion battery manufacturer Ability to put forward higher requirements. (3) Lithium manganate: there is a spinel structure and a layered structure, generally commonly used spinel structure.

The theoretical capacity is 148mAh / g, the actual capacity is between 100 ~ 120mAh / g, with a good capacity, stable structure, excellent low temperature performance, etc. However, its crystal structure is easily distorted, causing capacity attenuation, short cycle life. Important applications are high for security requirements and high cost requirements, but markets with energy density and cycle requirements.

Such as small communication equipment, charging treasure, electric tools and electric bicycles, special scenes (such as coal mines). In 2003, domestic manganate was started to industrialize. Yunnan Huilong and Lego Guoli first seized the low-end market, Jining unbounded, Qingdao dry transport and other manufacturers gradually added, capacity, circulating, powerful product diversified development to meet different applications market.

In 2008, the Legli put the lithium manganese acid lithium-ion battery was successfully applied to electric passenger cars. At present, the low-end market of manganese acid is important to be used in a communication battery, laptop battery and digital camera battery, laptop battery and digital camera battery. The high-end market is represented by the car market, and the performance requirements of the battery are more compared to the continuous development of the three-yuan material technology, and its market share in the vehicle is constantly decreasing.

(4) Lithium lithium phosphate: generally has a stable olivine skeleton structure, the discharge capacity can achieve more than 95% of the theoretical discharge capacity, the safety performance is excellent, the over-charge is very good, the cycle life is long, and the price is low. However, its energy density restriction is difficult to solve, and electric car users have continuously improved battery life. In 1997, olivine type lithium iron phosphate was first reported as a positive material.

North America's A123, Phostech, Valence has achieved mass production earlier, but because the international new energy automotive market is not as expected, unfortunate bankruptcy is acquired, or discontinued. Taiwan's Likai Electricity, Datong Sale, etc. In 2001, my country launched the material development of lithium iron phosphate.

At present, my country's phosphate positive material research and industrial development live in the forefront of the world. 1.2 Lithium iron phosphate ion battery work mechanism olivine-type structural material, hexagonal dense stacked arrangement, in the lattice of lithium iron phosphate positive material, P dominates the position of the eight-faced body, the void position of the octahedron by Li And FE filling, crystal octafabric and tetrahedomes form an integral spatial architecture, forming a sawtooth planar structure in close contacts of each point.

The phosphate ion battery positive electrode is composed of LiFePO4 of the olivine structure, and the negative electrode is composed of graphite, and the intermediate is a polyolefin PP / PE / PP diaphragm for isolating the positive and negative electrode, preventing electrons and allows lithium ions. During charge and discharge, the ion of the lithium iron phosphate ion battery is ion, the electrons are lost as follows: charging: LIFEPO4-XE-XLI + → XFEPO4 + (1-x) LifePO4 discharge: FePO4 + XLI + XE → XLifePO4 + (1-x) FePO4 When charging, the lithium ion is removed from the positive electrode to the negative electrode, and the electron is moved from the external circuit from the positive electrode to the negative electrode to ensure the charge balance of the positive and negative electrode, and the lithium ion is removed from the negative electrode, and the positive electrode is embedded by the electrolyte. This microstructure enables the lithium phosphate ion battery with a good voltage platform and a longer life: during charge and discharge of the battery, its positive electrode is between the LiFePO4 and the Six-Party Crystal FEPO4 of the slope.

Transition, since FEPO4 and LifePO4 coexist in the form of solid melt below 200 ° C, there is no significant two-phase turning point during charge and discharge, and therefore, the charge and discharge voltage platform of the lithium iron ion battery is long; in addition, in the charging process After completion, the volume of the positive electrode FEPO4 is only reduced by 6.81%, while the carbon negative electrode is slightly expanded during the charging process, and the use of volume changes, supporting the internal structure, and therefore, the lithium iron ion battery exhibits in the charge and discharge process. Good cycle stability, longer cycle life.

The theoretical capacity of lithium iron phosphate positive material is 170mA per gram. The actual capacity is 140mA per gram. The vibration density is 0.

9 ~ 1.5 per cubic centimeter, and the voltage is 3.4V.

Lithium iron phosphate positive material reflects good thermal stability, safe reliability, low carbon environmental protection, is the preferred positive material of large battery modules. However, the pilestance density of lithium iron phosphate positive electrode material is low, and the volume energy density is not high, limited application range. For the application limitations of lithium iron phosphate positive electrode materials, the relevant personnel can improve the conductivity of such materials by a method of doping high-priced metal cations in which high-priced metal cations are doped.

After a period of development, lithium iron phosphate is gradually developed, and it is widely used in many fields, such as electric vehicle sectors, electric bicycle fields, mobile power equipment, energy storage power fields, etc. Lithium iron phosphate positive material is widely used in the field of electric vehicles, especially the electric passenger, especially the electric passenger, especially the electric passenger, especially the electric passenger, in particular the unique advantageous, in particular the low resources of the cycle life, rich in resources, low prices. However, the lack of olivine crystal structure of lithium iron phosphate positive electrode material, such as low electrical conductivity, small lithium ion diffusion coefficient, etc.

, which causes low energy density, poor temperature resistance and error performance, etc. will be limited in the application area. Improve its disadvantages Important surface classes modified, vital phase doping modification, etc.

In recent years, my country's powered lithium-ion battery market has experienced explosive rising, battery technology is its core competitiveness. At present, power lithium-ion batteries are important including lithium iron phosphate ion batteries, lithium-manganese acid ion batteries and three-dimensional ion battery. Table 2 compares the performance of various types of lithium-ion batteries, where DOD is a depth depth depth (Discharge).

Lithium iron phosphate ion battery supports my country's lithium-ion battery material industry half-Wanjiang Mountain, which has considerable advantages in various batteries: lithium iron phosphate ion battery is relatively long, low heat generation, good thermal stability, and lithium iron phosphate Ion batteries also have good environmental safety. Lithium phosphate ion battery is applied to electric passenger cars with a lower price and stable performance, and the market share presents an upward situation. The material has the advantages of good safety, long cycle life, low cost, etc.

, is the main positive electrode material. Through nanochemical and surface carbon cladding, the performance of larger power discharge is achieved, and the carbon coated sample is well carried out without discretion, and my country has achieved the world's largest scale production. 2, Ningde Times and BYD led the CTP method, further reduce the cost of BYD Chairman Wang Chuanfu, when participating in the electric car, BYD has developed a new generation of phosphate ion battery "blade battery", this battery is expected to produce this year "Blade Battery" has increased by 50% higher than the traditional iron battery, with high safety, long-service life, with high safety, long-lasting life, can reach millions of kilometers, energy density can reach 180Wh / kg, compared to previous The increase is approximately 9%, which is no weakly weak than the ternary lithium ion battery of NCM811, and can solve the problem with low energy density of lithium iron phosphate ion battery.

This battery will be equipped in BYD "Han" in New Car, which is expected to be listed in June this year. What is a blade battery? In fact, it is a long battery method (important finger-shaped aluminum shell). Further improve the battery pack assembly efficiency by increasing the length of the battery (the maximum length is equivalent to the battery pack width).

It is not a specific size battery, but a series of batches of different sizes can be formed based on different needs. According to the description of BYD patent, the "blade battery" is a name of BYD's new-generation phosphate ion battery. It is BYD to develop many years of "superphosphate ion battery".

The blade battery is actually the length of BYD greater than or equal to 600mm less than or equal to 2500 mm, which is arranged in the array of "blade" inserted into the battery pack. The upgrade focus of "blade battery" is a battery pack (ie, CTP technology), which is a battery pack (ie, CTP technology), which is directly integrated to battery packs (ie, CTP technology). The blade battery pack is optimized by optimizing the battery pack structure, thereby increasing the efficiency after the battery pack, but does not have much impact on the energy density of the monomer.

By defining the arrangement in the battery pack and the size of the cell, the battery pack can be arranged in the battery pack. The monomer battery directly in the battery pack housing is optimized by the module framework. On the one hand, it is easy to dissipate heat through the battery pack housing or other heat dissipation components, on the other hand, can arrange more orders in effective space.

Body battery, can greatly increase the volume utilization, and the production process of the battery pack is simplified, the assembly complexity of the unit cell is lowered, the production cost is lowered, so that the battery pack and the weight of the entire battery pack are reduced, and the battery pack is realized. Lightweight. As the user's demand for the battery life of the electric vehicle gradually increases, in the case of limited space, the blade battery pack can be improved, on the one hand, the spatial utilization rate of the power lithium-ion battery pack, new energy density, and another Aspects can ensure that the monomer battery has a large enough heat dissipation area, which can be conducted to the outside to match higher energy densities.

According to the description of professional technicians, due to certain factors, such as peripheral components will occupy the internal space of the battery, including the bottom anti-attacking space, liquid cooling system, insulation materials, insulation protection, heat safety accessories, row Air passage, high voltage power distribution module, etc., the peak value of spatial utilization is usually approximately 80%, and the average space utilization in the market is about 50%, some or even as low as 40%. As shown in the figure below, by optimizing the module, reducing the spatial utilization of the component of the component (the volume of the cell volume and the wallpaper of the battery pack) is effectively improved, the space utilization of Comparative Example 1 is 55%, and the execution The spatial utilization rate of Example 1-3 was 57% / 60% / 62%, respectively; the spatial utilization rate of Comparative Example 2 was 53%, and the spatial utilization rate of Example 4-5 was 59% / 61%, respectively.

Different degrees of optimization, but there is still a certain distance from the spatial utilization rate peak. The heat dissipation performance in the battery module, BYD is controlled by setting the thermal plate (lower left Fig. 218) and the heat exchange plate to ensure the heat dissipation of the unit cell, and ensure that the temperature difference between the plurality of monomer batteries is not Be too big.

The thermally conductive plate can be made of a material having a good thermal conductivity, such as copper or aluminum such as a thermal conductivity. The heat exchange plate (bottom right Fig. 219) is provided with a coolant, and the cooling of the monomer battery is achieved by the coolant, so that the monomer battery can be in a suitable operating temperature.

Since the heat transfer plate is provided with a thermal conductive plate with a monomer battery, when cooling the monomer battery by the coolant, the temperature difference between the heat exchange plates can be balanced by the thermal conductive plate, thereby blocking a plurality of monomer batteries. Temperature difference control within 1 ° C. Comparative Example 4 and the monomer battery in Example 7-11, fast charge at 2C, measurement during fast charge, the temperature increase of the monomer battery.

It can be seen from the data in the table. In the patented monomer battery, in the fast charge of the same conditions, the temperature rise has different degrees of reduction, with superior heat dissipation effect, will When the cell module is loaded into a battery pack, the temperature rise of the battery pack has a decrease in battery packs. There is also the same utility as the "blade battery" and CTP technology.

CTP (CELLTOPACK) technology is to achieve battery-free group, direct integrated battery pack. In 2019, Ningde Times took the lead in using new CTP technology-free battery packs. It is indicated that the volume utilization rate of CTP battery packs increased by 15% -20%, and the number of parts is reduced by 40%.

The production efficiency is increased by 50%. After investing in the application, it will greatly reduce the manufacturing cost of the power lithium-ion battery. BYD plans to 2020, its phosphate monomer energy density will reach 180Wh / kg or more, and the system energy density will also increase to 160Wh / kg or more.

The CTP technology of Ningde Times is supplied with a battery pack, which meets the battery pack. Lightweight, improve the connection intensity of the battery pack in the whole vehicle. Its advantage is important to have two points: 1) CTP battery packs can be used in different models because there is no standard module restrictions.

2), reduce internal structures, CTP battery packs can increase volume utilization, system energy density is also indirect, its heat dissipation effect is higher than current small module battery pack. In CTP technology, Ningde Times pays attention to the convenience of battery module disassembly, BYD is more concerned about how monomeric batteries more loading and spatial utilization. 3, the blade battery and CTP method can reduce 15%.

We select the lithium-ion battery of Guoxuan's high-tech as our research object. Battery costs will have high reference to LFP batteries. According to the "September 17, 2019" related to the letter of the letter of the National High-Tech Public Distribution Costle Bundess Review Committee ", Guoxuan High-tech 2016-2017 The monolithic lithium phosphate ion battery is from 2.

06 yuan / wH, 1.69 yuan / wH, 1.12% / wH, 1.

00 yuan / WH, corresponding gross profit margin is 48.7%, 39.8%, 28.

8% and 30.4%, respectively. Therefore, according to the above two sets of data, we can calculate the manufacturing cost of the LFP battery.

In 2016, it is 1.058 yuan / WH, and in the first half of 2019, it has been less than 0.7 yuan / WH.

It is important because the cost of raw material is dropped from 0.871 yuan / WH in 2016 to 0.574 yuan / WH in the first half of 2019, absolutely drop 0.

3 Yuan / WH, relative to 34%. In terms of classification, in the total cost of manufacturing, the cost of raw materials has been stable since 2016, while energy costs, labor costs and manufacturing costs account for about 6%. We have continued to split the cost of raw materials, and we have found that the proportion of the positive and diaphragm in raw materials is large, approximately 10%, negative electrode, electrolyte, copper foil, aluminum shell cover, BMS cost, BMS.

Approximately from 7% to 8%, the battery box and the methyl group each account for about 5%, the remaining Pack and other costs, accounting for about 30% of the cost. It can be seen that the cost of the raw material can be divided into three major blocks in the LFP battery, one of which is four major raw materials (positive, negative electrode, diaphragm, electrolyte), total cost accounting for approximately 35%, Pack occupies 30 %, Surplus 35% for other raw materials and components. According to the above information, we give the following cost measurement assumptions: 1) The blade battery volume is about 50% higher than the energy density.

When the charge amount is constant, the volume decreases by more than about one-third, so that the aluminum shell cover is driven. Pack cost, assuming 33% decline 2) Energy, artificial, manufacturing cost, and BMS decline due to process optimization and reduction of parts, assuming 20% ​​reduction 3) further assume that raw materials (including positive electrode, negative electrode, diaphragm, electrolyte, copper foil , Methyl, battery case) price drop 20%, the total cost of LFP manufacturing can drop from 0.696 yuan / WH to 24.

3% to 0.527 yuan / WH. 4) Further considering the company's gross profit margin can be used to obtain actual sales prices, as shown in Figure 35, the blade battery and CTP method will only take the lead in commercial vehicles, although BYD announced, the blade battery method will be commercially used in Han However, commercial vehicles will still be a way to use.

We believe that BYD is commercially used in our own passenger car, which is to break through the general industrial logic: new technologies are often advancing on commercial vehicles, and passenger cars will be more cautious. BYD uses blade batteries on its own car, which is undoubtedly in the speed of promoting the passenger car. In fact, the blade battery and CTP method are the same, and it is in order to further reduce costs, while the monomer battery is large, and lithium iron phosphate is preferred.

Based on the 2019, there have been many first-line machine plants to use the CTP method to get on the test, so this technology is expected to use this technology in 2020. In accordance with the assumptions above, we calculate 10 meters or more, the battery cost is reduced by 30%, and the battery cost is reduced from 225,000 to 158,000. When there is no subsidy, the gross profit margin can be maintained.

We expect that 2020 phosphate's tamite's battery will be further enhanced in commercial vehicles. From the perspective of investment, the upstream phosphite is placed, and the downstream business vehicle profitability marginal improvement. Since the upstream of the entire lithium iron phosphate has passed through three-year shuffle, the industry concentration is high.

In the industrial chain, if you reach 10 suppliers, it is already very high in concentration, and there are only 3-4 suppliers of stable shipping third parties. So we believe that the leadload benefits. Suggests: German nano, Guoxuan high-tech, BYD and Yutong Bus.

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