1. Increased demand from multiple sources indicates a promising future for energy storage and power lithium batteries.
As more manufacturers join the new energy sector and the proportion of new energy power generation increases, high-energy-consuming industries such as charging piles and 5G base stations are developing rapidly, which also puts forward higher requirements for grid energy storage.
Catalyzed by these two major industries, the global lithium battery industry is experiencing continuous growth. According to data, China's lithium-ion battery shipments reached 131.6 GWh in 2019. It is predicted that by 2025, the global power lithium battery market will become a market worth hundreds of billions of yuan, with an annualized growth rate of over 14%, as shown in Figure 1.
Figure 1. Global Power Lithium Battery Industry Market Size Statistics and Forecast
Lithium batteries can be divided into three categories based on their application areas: consumer batteries, power batteries, and energy storage batteries. Consumer lithium batteries are traditional applications, such as batteries for mobile phones and laptops; power and energy storage are emerging fields with huge future market potential, such as power lithium batteries for new energy vehicles; energy storage lithium batteries mainly include energy storage power stations and photovoltaic energy storage, as shown in Figure 2.
Figure 2 Downstream applications of lithium batteries
The widespread use of batteries brings with it the issue of battery safety. The management, monitoring, and recycling of batteries require appropriate equipment and safety measures. Power supply suppliers need to consider and address how to match product parameters, performance, delivery time, and quality to the development of the lithium battery industry.
2. "Ultra-wide and ultra-high input voltage range" and "Small size and light weight"
In summary, the key power requirements of the lithium battery industry currently include the following:
1. Key Requirement 1: Input Voltage Range
Both power lithium batteries and energy storage have relatively large power outputs, resulting in high voltage when connected in series, and a large voltage fluctuation range. To convert this high voltage into usable electricity, the power module needs to have an ultra-wide and ultra-high input voltage range.
For lithium batteries, the voltage of a single cell ranges from a minimum of 2.5V to a maximum of 4.2V. If 32 cells are connected in series to form a module, the input voltage range reaches 80-135VDC. If eight modules are combined, the input voltage reaches as high as 1075V. In order to be compatible with applications with 1-8 modules, the power supply input voltage must meet the requirements of 80-1075VDC, as shown in Figure 3.
Figure 3 Lithium battery cell series module
2. Key Requirement Two: Small Size and Light Weight
Whether it's an electric bicycle or an electric four-wheeled vehicle, there are certain requirements regarding the overall size and weight of the vehicle, especially for the battery management system, which has even higher requirements for overall size and weight. Mornsun's low-power power supplies and RS-485 communication modules are widely used in automotive BMS.
3. Market-demand-based solution development
Typical power supply solution for the lithium battery industry
Photovoltaic energy storage system battery management system
Photovoltaic energy storage systems collect solar energy through photovoltaic modules and convert it into electrical energy. Part of this electrical energy is used to charge the battery through battery management, and the other part is converted by a DC-AC inverter to power the load, which can be the power grid or other electrical equipment. This section focuses on the battery management module, which has three functions: managing battery charging and discharging, balancing the battery string, and monitoring battery status.
The power supply scheme for the battery management module is shown in Figure 4. The front end is controlled by photovoltaic (PV) modules. Currently, the highest voltage across the series connection of these modules is between 1000V and 1100V. The PV40-27B12 product can be selected to achieve an operating voltage range of 200V to 1200V. PV modules are very unstable at low voltages, with large voltage fluctuations. The PV40-27B12 has undervoltage protection and a certain hysteresis, preventing it from constantly restarting due to voltage fluctuations. In addition to powering the battery management module, the PV40-27B12 also provides energy to other modules in the entire system.
Figure 4. Power Solution Block Diagram of Photovoltaic Energy Storage System Battery Management System
The F1203XT-1WR3 is used to power the battery status detection chip, which is signal isolated. The F1203XT-1WR3 can provide 3000V of power isolation to meet the functional isolation requirements.
Typical power supply solution 2 for the lithium battery industry
Power supply solution for BMS of two-wheeled vehicles
This lithium battery protection board for two-wheeled vehicles is primarily used in 14-cell battery packs for electric bicycles. It is compatible with lithium-ion, lithium polymer, and lithium iron phosphate cells of various chemistry. The protection board features overcharge protection, over-discharge protection, overcurrent protection, short-circuit protection, temperature protection, and charging balance management, as shown in Figure 5.
Figure 5. Power solution block diagram for a two-wheeled vehicle BMS
The front-end uses a non-isolated step-down chip to reduce the voltage from 60V to 5V. The back-end uses ST's MCU and our module for power supply. A domestically produced acquisition chip is used in the battery sampling section. This chip directly draws power from the battery pack. Our module provides isolated power to the 485. The front-end power supply uses MOSFET control mainly to achieve the requirement of low power consumption, because the 485 communication function can only be used in the charging management of the front-end.
Typical power supply solution 3 for the lithium battery industry
Smart Battery Cloud Management Main Control System
The intelligent battery cloud management system is a battery safety protection management system for the mobile Internet+ era. It can utilize cloud data processing and storage to achieve the purpose of long-term monitoring, inspection, data provision, analysis and diagnosis and abnormal status reminder services for battery operation status and life. It can also manage and adjust the equalization charging function. The entire system includes battery, battery management system, main control system and cloud data platform.
Figure 6 shows the application block diagram of the intelligent battery cloud management main control system. The entire system is connected to a 48VDC energy storage microgrid battery. Since the battery experiences both discharging and charging states, the power module is required to have a wide output voltage range. The power consumption under normal operating conditions is very low, only about 3W, while the maximum power for GPS data transmission is 10W. Therefore, the URB4815YMD-10WR3 product is sufficient. Simultaneously, the main controller needs to communicate in real-time with the energy storage BMS system's detection module to determine the battery status; here, RS-485 communication is selected.
Figure 6. Block diagram of the power solution for the intelligent battery cloud management main control system.
4. Insight into industry trends and meeting market demands
Driven by China's "new infrastructure" initiative and stimulated by overseas demand, the energy storage battery industry is accelerating its development. Currently, we are still in a period of rapid growth for new energy power lithium batteries, making technological improvements particularly important. The core concepts in the development of new energy power lithium batteries are safety performance, energy density, and environmental protection. Mornsun, based on its comprehensive power supply R&D platform, responds quickly to the application needs of lithium battery equipment, committed to providing the industry and customers with the highest quality power, and driving the industry's development further.
