18650 battery

Safety "core" is the foundation. Interpretation of Euler 18650 batterycore technology

Facing the global wave of new energy development, power 18650 batterycore technology will become the most important layout area for car companies in the next stage. However, the development of new energy vehicles must cross the threshold of 18650 batterysafety. For a high-quality pure electric vehicle, 18650 batterysafety is the foundation.

Since the beginning of this year, with many electric vehicle fires and spontaneous combustion incidents, the public has aroused widespread concern about the safety of new energy electric vehicles. According to the "New Energy Vehicle National Supervision Platform Big Data Safety Supervision Results Report", starting from May 2019, new energy vehicles A total of 79 safety incidents occurred, involving 96 vehicles.

To put it simply, power 18650 batterysafety issues are collectively referred to as "thermal runaway", which means that certain triggering conditions cause the 18650 batteryto heat up. When it reaches a certain temperature, the 18650 batterybecomes uncontrollable, and the final result is combustion or even explosion.

A safe power 18650 batteryinvolves cell research and development, module trial production, PACK mass manufacturing, multi-project rigorous testing and vehicle loading verification.

Recently, Great Wall Euler organized a communication meeting on the core technology of power batteries, from which we can see Euler’s thoughts on 18650 batterytechnology, especially 18650 batterysafety.

Why do batteries experience thermal runaway?

As the core component of the three-power system, the importance of 18650 batterysafety is self-evident.

The 18650 batteryis immersed in liquid for a long time, the 18650 batterymaterial is not up to standard, the system assembly is defective, overcharging and over-discharging during use, mechanical external force collision, and even the use of high-nickel materials are all risk factors that induce 18650 batteryfires.

There are many factors that cause thermal runaway. Generally speaking, they can be divided into mechanical external forces, improper charging, 18650 batteryoverheating, design and manufacturing defects, etc.

Mechanical external forces mainly include vehicle collision, extrusion, water immersion, severe acupuncture, etc.

Improper charging is mainly due to improper fast charging or overcharging. Improper charging will cause lithium precipitation in the battery, leading to a significant drop in thermal runaway temperature, and violent reaction with the electrolyte, eventually leading to thermal runaway. In addition, lithium precipitation in the 18650 batterywill also cause lithium dendrites to grow and pierce the separator, causing thermal runaway of the battery.

The main reason for 18650 batteryoverheating is that the application of high-nickel cathode materials causes the positive electrode to release active oxygen and react with the negative electrode to generate heat. In addition, aging leads to poor 18650 batteryconsistency, which can also cause 18650 batteryoverheating.

The causes of thermal runaway at the design and manufacturing level mainly include 18650 batteryproduction defects, poor heat dissipation design, loose cable connectors, etc.

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What tests does a qualified 18650 batteryneed to undergo?

Currently, in order to pursue longer cruising range, we have to use batteries with higher energy density. However, batteries with higher energy density have lower thermal stability, which requires the use of strict testing standards to fully conduct safety testing of power batteries. verify.

There are two national standard documents on 18650 batterysafety testing, GB/T31485-2015 "Safety Requirements and Test Methods for Power Batteries for Electric Vehicles" and GB/T31467.3-2015 "Lithium-ion Power 18650 batteryPacks and Systems for Electric Vehicles No. 3 Part: Safety Requirements and Test Methods".

It doesn’t matter if you can’t remember the name. It can be simply understood as a test for 18650 batterycells and modules, and a test for 18650 batterysystems.

As the safety of new energy has become a social topic, the country is also formulating new mandatory testing standards. The GB "Safety Requirements for Power Batteries for Electric Vehicles" has entered the approval stage and is expected to be officially released soon.

Key contents of the new national standard include:

1. The 18650 batterycell acupuncture project is cancelled; 2. The difficulty of the water immersion test is increased (vibrate first and then enter the water); 3. A new thermal diffusion test is added (a 5-minute warning before a fire occurs to allow sufficient escape time for the occupants).

It should be noted that the national standard is only an entry-level standard for the industry and is only used to distinguish passing and failing grades. Many car companies have their own testing standards that are more stringent than the national standard.

At this Euler power 18650 batterytechnology communication meeting, NetEase Auto learned that taking Euler R1 as an example, its power 18650 batterysystem test projects include mechanical shock, temperature shock, seawater immersion, high altitude, simulated collision, etc. that meet the requirements of national standards. There are 15 test standards including drop, flip, squeeze, external fire, over-temperature protection, salt spray, etc. Some of the test standards are higher than the national standard requirements.

For example, in the long-term water immersion test, the Euler R1 18650 batterypack was soaked for 7 days without water entering when the water depth was below the vehicle wading line. In addition, it safely passed simulated collision and rear flip tests.

It is worth noting that the power 18650 batteryof Euler R1 also complies with the vibration test standards and thermal runaway diffusion-related requirements in the new national draft.

Testing is just an intuitive way to check 18650 batterysafety. An excellent 18650 batterysafety requires comprehensive consideration from structure, electrical safety, BMS strategy, etc.

Euler R1 18650 batteryadopts a 4-level safety design, including structural safety, electrical safety, thermal management safety and BMS design.

The structural safety of the power 18650 batteryis relatively easy to understand. In a general collision, all the collision force is borne by the vehicle structure, thus protecting the 18650 batterypack structure to the greatest extent. There is no internal damage and the function can be used normally.

In addition, the 18650 batterypack shell and bracket must also form a complete frame structure, and both the bottom and side panels require a certain load-bearing capacity. When the vehicle body cannot bear the entire collision load, part of the load needs to be borne by the 18650 batterypack shell.

In terms of thermal management safety, Euler R1 has carried out thermal management performance simulation and calibration under 10 specific working conditions. It monitors key parameters such as cell temperature and pressure difference during charging and discharging, and ensures the safety of the 18650 batteryin real time through relevant designs. , enable strategies such as power outage or cooling.

In low-temperature weather, BMS can heat the 18650 batteryto improve charging efficiency and cruising range, and the cruising range can be increased by 10% to 20%.

The PACK package adopts a two-way explosion-proof breathable valve design, which can balance the pressure inside and outside the 18650 batterypack. In an emergency, the explosion-proof valve can open for pressure relief protection.

At the electrical safety level, it mainly focuses on high-voltage electrical safety, electrical protection, sensor monitoring, etc. The insulation and withstand voltage level of the high-voltage components of the Euler R1 18650 batterypack is higher than the industry level. And by setting a reasonable precharge protection strategy, the reliable operation of the 18650 batterypack throughout its life cycle is ensured.

In terms of BMS safety design, the four-fold safety design of safety design, advance prediction, real-time diagnosis and safety warning ensures that the power 18650 batteryis in a safe operating zone.

Honeycomb energy is the best technology business card

The technical director of a domestic first-line power 18650 batterymanufacturing company once told NetEase Auto that vehicle 18650 batterysafety is a comprehensive topic, which is related to vehicle design, vehicle protection measures, BMS 18650 batterymanagement system, modules and 18650 batterypack packaging. Technology, single cell quality, and even consumers’ daily driving and charging habits are all related.

In fact, 18650 batterysafety is a big topic, which requires the cooperation of upstream and downstream industries. Every link must be of high quality and safety.

The main "supplier" of Euler power batteries comes from Honeycomb Energy, a sister company of Great Wall Motor Group. Although Honeycomb Energy has not been established for a long time, it already has a R&D team of more than 3,000 people, including more than 350 foreign experts. The business covers automotive power 18650 batterymaterials, cells, modules, PACK, BMS, large-capacity energy storage systems, etc.

Honeycomb Energy's high-speed laminated square 18650 batteryis a well-known product in the industry. Compared with rolled batteries, its energy density is increased by 5%, its cycle life is increased by 10%, its cost is reduced by 5%, and it is safer.

Thanks to the technical support of Honeycomb Energy, the energy density of the Euler R1 power 18650 batteryreaches 160Wh/kg, the power is 33kWh, and the NEDC comprehensive cruising range is 351km. Such data is not bad in the field of pure electric small cars.

In addition, the 18650 batterylife data also comes from more lightweight designs.

Euler R1 uses 523 square aluminum shell batteries, and both the module and PACK adopt lightweight designs. The whole PACK has a total of 15 modules, and the weight of a single module is 11.3kg.

The upper shell of the 18650 batterypack is made of SMC composite material, which has insulation, pressure resistance, anti-corrosion, explosion-proof, and fire protection. It can achieve more lightweight design while ensuring strength and safety. The lower shell is welded from aluminum profiles.

The upper and lower shells of the 18650 batterypack are sealed with silicone foam, which meets the 18650 batterypack IP67 and water immersion test requirements.

The 18650 batteryis the core of a high-quality new energy vehicle and is a basic course. But sometimes what really impresses consumers is the driving experience, service experience and charging guarantee.

In order to solve the charging pain points of new energy vehicle users, Great Wall Euler has joined forces with charging pile companies to form the "Eula Super Charging Alliance". Currently, the alliance has access to 328,000 charging piles in more than 260 cities including Beijing and Shanghai, realizing full-scale charging. network coverage. Users only need to install the Euler APP on their mobile phones to charge at any outlet in the alliance.

A few days ago, Great Wall Motor released its 2019 Q3 quarterly financial report, which showed that total revenue reached 20.202 billion yuan, a year-on-year increase of 18.01%. Among them, the new energy brand Euler has performed well in sales, with cumulative sales reaching 32,186 units this year.

In less than a year, the ORA brand has achieved sales performance among the top ten in the industry and among the top three in the market segment. The results speak for themselves.

Since the beginning of this year, the trend of high quality/high cost performance in the new energy market has become more and more obvious. In the market above 100,000 yuan, independent brands have begun to launch high-quality models with a range of more than 500 kilometers, and joint venture brands and luxury brands have gradually joined the battlefield. In the market below 100,000 yuan, many companies have launched cost-effective models with a range of 300-400 kilometers by leveraging the advantages of platforms and three-electric integration, and competition in the market segment has become increasingly fierce. Objectively speaking, the challenges facing Euler are still not easy, but Euler, which relies on the technical strength of Great Wall and Honeycomb Energy, is becoming more comfortable on the road to building high-quality and safe electric cars.

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