Benefits of High-precision EV Battery Formation and Grading System

Consumers' new energy vehicle purchase decision mainly depends on the three main factors of safety, cost and mileage. This is also the goal of the joint efforts of new energy vehicle manufacturers and power battery manufacturers.

Among them, the cost and mileage of electric vehicles are highly related to a key process of EV battery cell manufacturing- EV battery formation and grading process, which is a key test link in the later stage of battery manufacturing.

The formation and grading of battery cells are the key to the manufacturing process of lithium-ion batteries. Both are achieved by precise control of the battery charging and discharging process.

The battery cell formation acts to "activate" the battery, making the battery begin to have the ability to store and release electrical energy. The battery cell grading is to sort the batteries with similar characteristics, improve the consistency of the finished battery cells, and ensure the high performance of the EV power battery pack.

Lithium-ion battery formation and grading testing is a time-consuming process that involves multiple battery charging and discharging to activate the battery's chemistry. However, this process is very necessary and essential to ensure the reliability and quality of the finished battery cells.

Lithium-ion battery formation and grading accounted for more than one-third of the total cost of the lithium-ion battery cell manufacturing process, so the battery formation and grading system once became one of the bottlenecks that hindered battery cell manufacturers from increasing output and reducing the total cost of battery production.

Lithium-ion battery manufacturers are eagerly looking forward to reducing the time required for battery formation and grading under the premise of ensuring safety in this field, collecting and monitoring the parameter changes of lithium batteries from more dimensions and with greater density, so that the lithium battery charge and discharge process becomes more efficient and energy-saving, reducing equipment footprint, and reducing cable usage and heat generation, ultimately reducing costs and improving energy efficiency.

In addition, in order to improve the cycle life, stability, self-discharge, safety and other electrochemical properties of the battery, the consistency of the lithium battery cells must be strictly controlled or the battery grade must be accurately evaluated, so the current and voltage measurement accuracy of the battery formation and grading equipment are high demands.

For battery test equipment manufacturers, it is no easy task to meet efficient and accurate battery formation and grading testing. In the analog front end, the power supply that drives the battery charging circuit needs to be strictly controlled. From a deeper analysis, the battery formation and grading test needs to closely monitor the current and voltage distribution used during the battery cycle to prevent overcharge and undercharge. WinAck is one of the few professional-level suppliers that can meet the requirements of battery manufacturers for accurate testing of battery formation and grading.

WinAck's battery formation and grading machine can improve the accuracy and efficiency of the formation and grading system of lithium-ion batteries. In addition, the technology adopted by WinAck can recover the energy of the battery during discharge, and the accuracy is significantly higher than that of traditional solutions. Higher accuracy also means that more batteries can be placed in the battery pack, which helps to extend the application of electric vehicle's battery life.

At the same time, the WinAck battery-based composition system also has excellent detection and monitoring functions, which can effectively prevent overcharging and undercharging that may cause battery failures, thereby improving the safety of the battery manufacturing process.

In order to produce batteries faster at a lower cost and obtain the capacity of lithium batteries more accurately, the battery formation and grading system uses hundreds of channels. Therefore, the accuracy requirements of the current and voltage measurement during the charging and discharging process of the lithium battery are significantly improved.

The accuracy of current and voltage control during battery charging and discharging largely determines the reliability of lithium battery consistency control. High-performance instrumentation amplifiers and related parallel resistors are required to measure battery charging and discharging current, even in harsh factories. Under the conditions, the accuracy of ±0.05% or more must be achieved, and the differential amplifier used to monitor the voltage in the entire thermal operating range must also be suitable for this accuracy level.

In fact, it is a huge challenge to combine the above functional components into a complete and accurate lithium-ion battery formation and grading solution, and to improve performance and reduce system footprint as much as possible.

WinAck has leading instrumentation amplifier technology. By integrating high-performance instrumentation amplifiers or differential amplifiers and gain setting resistor networks into the chip, WinAck can design control loops to reduce calibration time, reduce ripple, current sharing control and other intelligent controls Function, provide a high level of current and voltage measurement accuracy, reduce the calibration cycle time and number of times, and further increase the normal running time. In addition, the higher switching frequency brings simplification of design and reduction of the volume of electronic components, and also reduces the number of required components and the layout of the charge and discharge circuit board.