High-precision testing solution breaks through 18650 battery 3500mah cost and range anxiety

　　Although the new energy vehicle industry has been through a rough patch, it has great prospects. Leading companies in vehicle and battery industries are actively planning for the next industry cycle after the withdrawal of subsidies.

　　Among them, safety, cost and mileage are the three major factors for consumers to decide to purchase new energy vehicles, and have become the joint efforts of OEMs and 18650 battery 3500mah manufacturers.

　　There is no doubt that mastering the security of the 18650 battery 3500mah supply chain and achieving stronger cost and performance competitiveness from the 18650 battery 3500mah manufacturing end are the keys for companies to win in the increasingly fierce market competition.

　　Among them, volume fractionation is a key process in 18650 battery 3500mah manufacturing and is highly related to the cost and mileage of power batteries.

　　Capacity formation is a key testing step in the later stages of battery manufacturing. As a major provider of high-performance simulation technology, Analog Devices' insights on how to improve 18650 battery 3500mah performance and reduce costs from the manufacturing stage may serve as an industry reference.

　　01 Break through manufacturing costs and mileage anxiety from key links

　　At present, 18650 battery 3500mah manufacturers are generally in the dilemma of battery "anxiety". Generally speaking, the lithium-ion battery manufacturing process is very complex, including electrode production, stacking structure and cell assembly, followed by electrical testing to evaluate the battery capacity and performance and in-service ratings.

　　Volumetric formation is the key to the manufacturing process of lithium-ion batteries. Both are charged and discharged processes through precise control of the battery. The former plays an "activation" role, allowing the battery to begin to have the ability to store and release electrical energy. The latter It is to sort batteries with similar characteristics to improve the consistency of finished batteries and ensure the high performance of vehicle 18650 battery 3500mah packs.

　　This is a fairly time-consuming process that involves multiple charges and discharges to activate the battery's chemistry. But this process is very necessary and crucial to ensuring the reliability and quality of the finished battery.

　　Lithium-ion battery manufacturing process

　　Volumetric conversion of lithium-ion batteries accounts for more than one-third of the total cost of the manufacturing process. Therefore, volumetric conversion once became one of the bottlenecks that hindered battery companies from increasing production and thereby reducing the total cost of battery production.

　　18650 battery 3500mah companies are also eager to reduce the time required for volume separation while ensuring safety in this field, and to collect and monitor parameter changes of lithium batteries from more dimensions and with greater density, making the charging and discharging process more efficient. Save power, reduce equipment footprint, and reduce cable usage and heat, ultimately reducing costs and improving energy efficiency.

　　In addition, in order to improve the electrochemical performance such as cycle life, stability, self-discharge, and safety of the battery, the consistency of the lithium battery must be strictly controlled or the battery grade must be accurately evaluated. Therefore, the current and voltage measurement accuracy of the formation and capacity dividing equipment has certain requirements. Very demanding.

　　Therefore, after comprehensively considering factors such as cost, 18650 battery 3500mah companies are more inclined to work closely with suppliers who have expertise in formation testing systems. Not only can they obtain more complex components and building blocks, but they can also obtain more easily adoptable components. The reference design of the system architecture makes the time to market three to four times faster than developing a formation and test system from scratch. It also ensures the accuracy and reliability of battery formation and test measurement.

　　For battery testing suppliers, it is not easy to meet the requirements of efficient and accurate battery capacity and formation testing. On the analog front end, the power supply driving the battery charging circuit needs to be tightly controlled.

　　On a deeper level, battery formation and testing requires close monitoring of the current and voltage distribution used during battery cycling to prevent overcharging and undercharging.

　　ADI is one of the few professional-grade suppliers that can meet the precise battery formation testing needs of battery manufacturers.

　　ADI innovations deliver measurable results to battery formation and test equipment manufacturers

　　02 "Budget-conscious" battery testing system-level solution

　　Currently, there are two solutions for formation and testing in the production process of lithium-ion electronics: one is a linear solution and the other is PWM (Pulse Width Modulation). The power consumption of the linear solution will be relatively large and better heat dissipation equipment is required.

　　The solutions currently on the market are also differentiated according to the size of the battery capacity. Small-capacity ones will still use linear solutions, which have low efficiency but low equipment costs. When it reaches above 6A, the power consumption will increase, and the PWM method becomes more appropriate.

　　ADI's battery capacity-dividing charge-discharge integrated chip AD8452 contains the crystallization of ADI's analog technology, which can improve the system accuracy and efficiency of lithium-ion battery formation and capacity division.

　　Compared with traditional technology, by integrating a high-precision front-end amplifier and a high-frequency PWM controller, the AD8452 can provide 50% more channels in the same space, thereby expanding capacity and increasing battery yield. Each AD8452 can individually control a charge and discharge current of up to 30A, or multiple AD8452s can be connected in parallel to control a larger output current.

　　In addition, the switching technology used in the AD8452 can recycle battery energy during discharge, with significantly higher accuracy than traditional switching solutions. Higher accuracy also means that more cells can be placed in the battery pack, helping to extend the life of electric vehicles. battery life of other applications.

　　At the same time, the AD8452 also has excellent detection and monitoring functions, which can effectively prevent overcharging and undercharging that may lead to battery failure, thus improving the safety of the manufacturing process.

　　The device has a supporting system simulation demonstration board, which can reduce R&D engineering costs and shorten time to market for test equipment manufacturers. It also allows manufacturers to design systems with more functions and more reliable test processes.

　　In order to produce batteries faster at lower cost and obtain the capacity of lithium batteries more accurately, battery systems use hundreds or thousands of channels during the formation and testing stages. The tester topology depends on the total energy capacity of the system. The error requirements for current and voltage measurement of lithium battery charging and discharging have also increased significantly.

　　The current and voltage control accuracy during the charge and discharge process largely determines the reliability of the consistency control of lithium batteries. High-performance instrumentation amplifiers and related parallel resistors are required to measure battery charge and discharge current, even under harsh factory conditions. , it is also necessary to achieve an accuracy of more than ±0.05%, and the differential amplifier used to monitor the voltage throughout the thermal operating range also needs to be suitable for this accuracy level.

　　Many customers require voltage testing to achieve an error accuracy of 5 to 1/10,000ths, which increases the error requirements for amplifiers and ADCs/DACs in the entire measurement control circuit.

　　In fact, it is a huge challenge to combine the above functional components into a complete and accurate solution with the highest possible performance and reduced system footprint. It is also a huge challenge for ADI to integrate the analog front end, power control and monitoring circuits in a single ICAD8452 one of the reasons.

　　ADI has leading instrumentation amplifier technology. By integrating a high-performance instrumentation amplifier or differential amplifier with a gain setting resistor network into the chip, the AD8452 can be intelligently controlled through control loop design, reduced calibration time, ripple reduction, current sharing control, etc. function, providing a high level of current and voltage measurement accuracy, reducing calibration cycle time and frequency, further increasing uptime.

　　In addition, higher switching frequency brings about simplification of design and reduction of the size of electronic components. It also reduces the number of required devices and the layout area of charging and discharging circuit boards, saving up to 50% of the bill of materials (BoM). All control operations can be completed in the simulation domain without the need to develop complex algorithms, so this method can also effectively reduce software development costs.

　　At the same time, ADI’s current detection amplifier calibration and calibration technology simultaneously improves the consistency control capabilities of lithium batteries from multiple dimensions, and also contributes to the popularization of environmentally friendly technology.

　　As Zhao Yimiao, general manager of ADI's System Solutions Division, pointed out: "China's manufacturing industry is very fast in following up on emerging industries, and there is not much gap with the world's advanced level. For example, the booming development of the lithium battery industry has driven the production and testing of lithium batteries. demand, Chinese manufacturers are currently at the forefront of lithium battery testing.”

　　Battery technology is an important driving force for new energy vehicles. How to improve the measurement accuracy and service life of batteries, increase battery endurance, reduce costs, and ensure safety are challenges faced by the entire industry.

　　In these areas, ADI is actively conducting research and has achieved a series of cutting-edge research results. For customers who have reached strategic cooperation intentions with ADI on the AD8452, ADI is willing to discuss and cooperate with each other on the future of lithium battery decomposition.

Read recommendations:

Ni-MH AA1500mAh 1.2V

Analysis of the causes of zero voltage in lithium batteries!button cell battery cr1620

Lithium battery steel shell/aluminum shell/cylinder/flexible packaging series

lifepo4 battery calb 200ah 3.2v

AAA NiMH batteries