Last week, we introduced the mechanism of lipo battery 6s 1200mah group inconsistency. Today, CNHL, the manufacturer of lipo battery 6s 1200mah, will introduce the optimization method of lipo battery 6s 1200mah group inconsistency in detail. Interested partners may wish to spend a few minutes Time to visit with me.
1. single lipo battery 6s 1200mah manufacturing technology
Guaranteed batch consistency of lipo battery 6s 1200mah material
The positive electrode materials of the lipo battery 6s 1200mah are ternary materials, lithium iron phosphate, lithium cobaltate and lithium manganate, etc., and the negative electrode materials are graphite, silicon and lithium titanate. The same batch of raw materials is very important for the consistency of the performance of lipo battery 6s 1200mah. During the production process, it is necessary to strictly control the parameters such as particle size distribution, specific surface area and impurity content of the raw materials to ensure the batch consistency of raw materials.
Improve the consistency of lipo battery 6s 1200mah production process
The production process of lipo battery 6s 1200mah consists of multiple processes, and each process may affect the consistency of lipo battery 6s 1200mah. In order for the performance of the production monomer to be consistent, each process must be reasonably designed and controlled so that it can be repeated in parallel. According to the performance requirements of lithium batteries, the lipo battery 6s 1200mah production process is designed, and the influence of parameters such as raw materials, electrodes and electrolytes on the consistency of lithium batteries is analyzed, so as to reasonably control the thresholds of each process parameter. The reduction of human intervention in the production line and the realization of automation can also improve the consistency of the lipo battery 6s 1200mah.
2. single lipo battery 6s 1200mah sorting system
In order to reduce the adverse effect of the initial state difference on the lipo battery 6s 1200mah group, it is usually necessary to screen the single lipo battery 6s 1200mah, and combine lithium batteries with more consistent state parameters. The grouping methods of lipo battery 6s 1200mah mainly include single parameter matching method, multi-parameter matching method and dynamic characteristic curve matching method. The dynamic characteristic curve matching method can well reflect the characteristics of the lipo battery 6s 1200mah by comparing the difference between the charge and discharge curves of different lipo battery 6s 1200mah under the same magnification, and the sorting effect is ideal.
3. lipo battery 6s 1200mah external circuit
Lithium battery series and parallel mode
The connection method of the battery pack affects the consistency of the lithium battery. At present, there are two better connection methods: first connect two identical batteries in parallel as a module, and then connect the modules in series (PSB); first connect two different lipo batteries 6s 1200mah in series as a module, and then connect the modules in parallel ( SPA).
lipo battery 6s 1200mah management system
In order to improve the performance and service life of the lipo battery 6s 1200mah, it is necessary to manage and maintain the single lipo battery 6s 1200mah. The lipo battery 6s 1200mah management system is an important guarantee for the normal operation of the lipo battery 6s 1200mah system. The main task is to ensure the performance of the lipo battery 6s 1200mah group, prevent damage to the lipo battery 6s 1200mah, avoid safety accidents, and make the lipo battery 6s 1200mah in a suitable area work inside to prolong life. BMS is composed of sensors, actuators, controllers and signal lines. The main functions are: data acquisition, state estimation, charge and discharge control, balanced charging, heat management, safety management and data communication.
Although the lipo battery 6s 1200mah management technology has been widely used, it still needs to be improved, especially in terms of SOC estimation and data acquisition accuracy, balance circuit, and lipo battery 6s 1200mah fast charging. Since different types of lipo battery 6s 1200mah have different characteristics, the BMS suitable for all lipo battery 6s 1200mah is the main research direction at present.
In order to alleviate or even eliminate the inconsistency between the individual lipo battery 6s 1200mah groups in the lipo battery 6s 1200mah group and improve the performance, life and safety of the lipo battery 6s 1200mah group, the lipo battery 6s can be effectively improved through balanced circuits and balanced control strategies Inconsistency in the 1200mah group.
Equalization circuit topology: The research of equalization circuit topology is mainly to design and improve the equalization circuit structure, improve the equalization efficiency and reduce the cost. According to whether the circuit consumes energy during the balancing process, it can be divided into energy-consuming balancing and non-energy-consuming balancing.
The energy-consuming balancing circuit uses energy-consuming components to consume the power of the lipo battery 6s 1200mah with the higher voltage in the lipo battery 6s 1200mah group, so as to achieve the consistency of the single lipo battery 6s 1200mah, the circuit is simple, the balancing speed is fast, and the efficiency is high, but it will lead to The energy utilization rate of the lipo battery 6s 1200mah group is not high; the non-energy-consumption type circuit uses energy storage elements and balanced external circuits to realize the energy transfer between the lipo battery 6s 1200mah, high energy utilization efficiency, and the non-energy-consumption type balance has switched capacitor type, Converter type and transformer type.
Balance control strategy: The balance control strategy is mainly to determine the working mode of the balance module. At present, the working methods include maximum value balance method, average value comparison method and fuzzy control method. The improvement of balancing ability is an important direction of lipo battery 6s 1200mah consistency research. Equalization technology needs to be further improved, including:
(1) SOC is the most ideal judgment standard, and the real-time estimation accuracy needs to be further improved;
(2) the topology of the equalization circuit is optimized, the equalization speed is improved, and the equalization time is shortened;
(3) the equalization control strategy needs to be optimized to determine the most Find the best equalization parameters according to the equalization circuit to achieve the purpose of fast equalization.
At present, the research on equalization control strategy mostly focuses on the design and realization of equalization hardware circuit. But the equalization circuit parameters will affect the equalization effect. In addition, the state of charge of the lipo battery 6s 1200mah, the balance threshold, the charge and discharge current, the ratio of the balance current to the charge and discharge current, and the switching method of the charge and discharge conditions will also affect the balance effect when the balance is started.
4. lipo battery 6s 1200mah charging and discharging strategy
Scientific and reasonable charging and discharging strategies can improve the energy utilization efficiency of lipo battery 6s 1200mah. At present, the best charging method for comprehensive performance is the lipo battery 6s 1200mah management system and the charger to coordinate and cooperate in series charging. Through BMS, the ambient temperature of the lipo battery 6s 1200mah group, the voltage and current of the single lipo battery 6s 1200mah, the consistency and temperature Upgrade status monitoring, data sharing with the charger, real-time change of the output current, can prevent lipo battery 6s 1200mah overcharge and optimize charging. This charging method is the current mainstream, which can eliminate the problems of poor consistency, low charging efficiency and inability to fully charge the lipo battery 6s 1200mah group when charging to a certain extent.
5. lipo battery 6s 1200mah thermal management
The heat production and heat dissipation of each single lipo battery 6s 1200mah in the lipo battery 6s 1200mah group are unevenly distributed in space, which will cause the temperature of the lipo battery 6s 1200mah itself, some areas of the lipo battery 6s 1200mah group and the environment to be inconsistent, such as If it is not controlled, the temperature difference inside the lipo battery 6s 1200mah group will continue to expand, which will accelerate the performance degradation of the lipo battery 6s 1200mah. Therefore, thermal management of the lipo battery 6s 1200mah group is required.
Thermal management systems usually require compact structure, light weight, easy packaging, reliability, low cost, and easy maintenance. Its functions are: make the lipo battery 6s 1200mah operate in the most suitable temperature range; reduce the temperature difference between the lipo battery 6s 1200mah, within the module and between the modules. Thermal management is divided into active and passive ways. The heat transfer medium used in the system can be divided into three categories, namely air, liquid and phase change material.
At present, the thermal management research of the lipo battery 6s 1200mah group has limitations.
For example, the thermal model of the lipo battery 6s 1200mah is too simplified. The lipo battery 6s 1200mah monomer often uses a zero-dimensional heat generation model. The heat generation rate of each part of the lipo battery 6s 1200mah is the same. A performance comparison of different thermal management systems based on non-uniform internal heat sources is lacking. There are few studies on low temperature characteristics and low temperature thermal management technology of lithium ion lipo battery 6s 1200mah.
Well, the above is all the content brought to you by CNHL today. For more information about lipo battery 6s 1200mah, please refer to our previous articles:
Detailed explanation of the development trend of 1s lipo battery
How big is the 6s lipo battery recycling market?