With the rapid development of the electric vehicle market, inefficient automobile batteries will become a great burden to the environment after several years, and battery recycling and reuse will become an important key to reduce the cost of electric vehicles and realize environmentally sustainable development. This article will show you the important issues of battery recycling and reuse in electric vehicles, as well as the wireless battery management systems (wBMS) technology and related solutions introduced by ADI.
Battery recycling is the key to the development of electric vehicles
Because electric vehicles (EVs) don't have internal combustion engine, you may not hear them running, but more and more EVs are quietly becoming the main force on the road. In fact, according to the World Economic Forum, 2.3 million EVs were sold in 2020, a fourfold increase over the sales of EVs five years ago. Consumer demand, the development of EV battery charging infrastructure, and cities and countries laws and regulations conducive to electrification have all contributed to this dramatic transformation. Although EVs are boasted of as green alternatives to internal combustion engines and fossil fuels, it has a fatal weakness in what happens to all these half-ton EV batteries when they are no longer able to store enough power to drive the vehicle.
About 10 million EVs are already driving on the road. It is estimated that 10 million EVs will be sold annually by 2025. Given that the average useful life of EV batteries is about 10 years, the total number of EV batteries discarded each year by 2035 will be 1.3-1.5 times the mass of the Great Pyramid of Giza (5.8 million tons).
Therefore, EV battery recycling will be a very common option, but the process can only recover some raw materials (e.g. cobalt and lithium), not all of them. However, EV battery recycling is costly, unregulated, and lacks a clear supply chain, leading to the increasing cost of disposing of waste batteries.
Batteries are still the main concern of the cost efficiency of EVs, because batteries are the core of EVs, accounting for about 30% of the total cost of EVs. However, battery technology is about to be significantly improved. Major advances in battery chemistry and electronics can reduce costs, realize efficient battery reuse and second life, and promote battery recycling in EVs, thus providing cost advantages for promoting the popularity of EVs.
In order to improve the efficiency of automobile battery recycling, it is necessary to carry out effective battery health monitoring during the first use and any subsequent life cycle of the battery, which will help build trust between the battery buyers and sellers. Based on this trust, OEMs can use batteries as assets to compensate for some initial battery investment and indirectly transfer the value of the savings to consumers.
wBMS can improve the second life efficiency of batteries
Battery reuse is the process of identifying batteries cells within a battery that retain available power, disassembling the battery, and reassembling these available battery cells. This alternative recycling approach (or more accurately, this transitional approach) is emerging in the form of "battery second life". Replacement is required when the automobile lithium-ion battery charging capacity drops to 70-80% of the original capacity (usually after 8 to 10 years) and the automobile can no longer be effectively powered. The increasing number of these batteries that are no longer in use creates new market opportunities – the "second-life battery sector”.
In the next five years, the number of EVs on the road will be five times that of today. Reuse and recycling of battery assets of electric vehicles will help to develop a circular economy, save energy, and create value for consumers. Since battery pack costs account for more than 30% of EV prices, obvious economic and environmental incentives can motivate battery manufacturers, automobile manufacturers, regulators, and even insurance companies to actively nurture a secondary market.
The most direct way to reuse is through the application of energy storage systems (ESS), which allow batteries that remain usable in old batteries to be reused in renewable power grids to store excess power generated by wind, solar, hydroelectric, or geothermal power plants. EV batteries can also be disassembled into smaller battery modules for less demanding uses, such as power tools, forklifts, or electric scooters.
The emerging second-life battery market is not accessible in terms of technology, quality control, and implementation hurdles. For example, EV batteries today use an electrical harness to monitor battery state-of-charge. These harnesses (and other harnesses) must be completely removed before the batteries can be redeployed, adding to cost and design complexity. Considering end-of-life disassembly in product design will be a trend in which designers can use wBMS technology to replace hardwired battery monitoring systems (BMS). The elimination of wiring harnesses in wBMS will provide a lot of opportunities. wBMS not only reduces the size, weight, and material cost of electric vehicles, but also allows for safer and more scalable robotic disassembly and assembly processes for batteries, thus improving the efficiency of battery transition to second-life applications.
Battery second life can prolong the life of EV batteries
For EVs, the core element is of course the battery. BMS is very important to maximize the reliability and service life of batteries and promote the popularization of EVs. The higher the accuracy of BMS, the better it is able to ascertain the status of battery cells, the more capacity it can obtain, and the more reliable the operation of the battery pack.
It is estimated that battery echelon utilization can extend battery life by 6 to 30 years. However, this period ultimately depends on battery usage during the first application. Then, if the wBMS technology can collect battery data contactless throughout the battery life cycle, it has other important advantages. This important data can be integrated into the cloud and related to the safety characteristics of the battery.
Before deciding to let the battery enter second-life applications, the seller can use this data to generate a state-of-health history, such as how many times the EV owner has completely/partially charged and discharged the battery? Has the EV ever had an accident? What can be seen from the vehicle maintenance records? In addition, this sophisticated health monitoring can be applied where data collection is logically impossible, including whether new batteries or second life batteries are properly stored in the warehouse. Has anything happened during the transportation?
After use and reuse, all batteries are eventually broken down and recycled. The wBMS technology allows for the mass characterization of inventory information without contact and facilitates rapid decision making for reuse or recycling. Once reuse or recycling is decided, the buyer and seller can establish a normalized level of trust by using state-of-health data (realized by wBMS and other technologies) and fairly assess the value of batteries before reaching a sales price. The industry could even develop a rating criterion to differentiate between lightly used AAA-rated batteries and poorly maintained batteries.
Regeneration of EV batteries to achieve the goal of environmental sustainability
EVs are growing rapidly, and batteries will play a key role in promoting environmentally friendly transportation. Although second-life battery reuse sector is a high-value intermediate step before recycling, its success depends on the overall use of batteries in initial and follow-on applications. The overall service life of the battery must be considered when designing the battery and BMS. This may require battery suppliers and automobile manufacturers to change their way of thinking, but in the long run, they can play an important role in creating new market channels with environmental sustainability and economic feasibility.
In addition, the automotive industry is developing many measures related to the environment and society, which will produce benefits now and in the future. These include eliminating cobalt from battery chemicals (because of the controversial mining practices) and reducing emissions from the production of automotive materials such as aluminum and plastics, all of which are aimed at achieving zero-carbon vehicles.
ADI is also actively committed to achieving environmentally sustainable development goals, including achieving zero net emissions by 2050, carbon neutrality by 2030, reducing CO2 and CO2e emissions, and reducing water consumption of all facilities by half by 2030.
Therefore, in the near future, we will all feel good about driving environmentally-friendly EVs. What is even more gratifying is that EV batteries will be reborn in second life and continue to play a role in future vehicles, ESSs, or other applications.
wBMS system specially designed to meet battery management requirements
ADI's wBMS is a special solution tailored to meet the requirements of high reliability and low latency of automotive battery management systems. wBMS networks can provide robust connectivity for monitoring battery cells and controlling the balanced current in EVs or other large ESSs.
wBMS consists of software developed by ADI, which resides on a specially developed system-on-chip. This low-power integrated system-on-chip includes a 2.4 GHz ISM band radio and an embedded microcontroller (MCU) subsystem. These devices can provide wireless communication between the battery cell monitoring chip and the battery management system controller (BMS controller).
ADI's wBMS devices include a low-power 2.4 GHz wireless system-on-chip ADRF8801 and ADRF8851, as well as a low-power 2.4 GHz wBMS node ADRF8800 and 2.4 GHz low-power wBMS manager ADRF8850, which will meet various battery management requirements of EVs. ADI's wBMS devices will reduce the material cost, increase the design flexibility, effectively promote the mass production of EVs, make them more competitive than traditional internal combustion engine vehicles, and provide a key boost for realizing the future of renewable energy.
Conclusion
Although EVs emphasize lower carbon emissions and more environmental protection than fuel vehicles, if the problem of battery reuse and recycling cannot be solved, the goal of environmentally sustainable development will not actually be achieved. Through wBMS technology, the efficiency of battery reuse and recycling can be improved, and the cost of EVs can be indirectly reduced, which will be an important key to the development of EVs, and ADI's wBMS solution will play an important role in battery second life.