Batteries have been used and are present in more and more parts of our lives since their discovery in 1800. They are becoming a key factor on the fight against climate change by enabling the shift from fossil fuel to renewable energy but also helping in the access to electricity for off-grid communities.

From 2010 to 2018, battery demand growth was 30% annually, reaching to 180GWh in 2018. Market studies expect to keep the growth up to 25% annually in the best-case scenario up to 2030. The main driver of the growth will be the electric vehicle (EV) which will expect to be more than 88% of the demand compared to other applications.

As the essential component of EV, the battery will need to be replaced, discarded and recycled. Therefore, the growth in the demand comes along with an increasing environmental concern related to the discarding of these batteries.

In order to tackle the issue, engineers and lawmakers are considering the reconditioning of these EV batteries in energy storage systems solution for other applications. The general term for this concept is the ‘‘Second-Life Battery (SLB)’’ where electric vehicles are considered as the primary source of these. This solution will provide new economic income and will address environmental concerns.

In electric vehicles, the battery life is estimated at 8 years (around 160.000 km of traveling) based on the car manufacturer’s battery guaranty. After this use, the remaining power and kinetic of the batteries are considered not enough to fulfill the requirement of mobility application. However, the remaining energy inside the battery pack and cells can be used in other applications where studies estimate at 5-10 years to reach the end of life depending on the second life application.

In order to be used in second-life applications, these batteries need to go through different stages and processes. These may depend on the level of dismantling (pack, module, cell or components) that is nowadays manually performed due to the lack of regulatory framework. It is also recommended to have the battery totally discharged for safe handling.

Finally, regarding disassembling – assembling, it is also necessary to consider that the cell comes in three different formats (cylindrical, pouch and prismatic) where each type have is one specificity. Therefore, the all-reconditioning process will require a highly qualified workforce and set off knowledge.

Advantages of Second Life Batteries

Despite all these additional steps, some study previsions have evaluated the cost of Second-Life Batteries might be half of the price of fresh batteries  and potentially provide substantial financial opportunities for individuals and companies that in fine will help to reduce the cost of EV battery. Furthermore, new companies could be created that will take charge of the reconditioning process of the discarded batteries.

Second, the market of SLB in stationary applications could also benefit from cheaper solutions for their Electrochemical Energy Storage (EES). Finally, the recycling industry could also take advantage of batteries that don’t reach the requirements of the SLB application.

Apart from the economic perspective, the use of SLB will also have an impact from an environmental point of view. The concept of Zero waste management is applied by using SLB to prevent the creation of waste as well as to reach the circular economy. Besides, the use of Second-Life Batteries to Electrochemical Energy Storage for stationary applications will extend the life cycle of the battery.

The additional environmental benefit is the impact of reduced demand for new batteries. Therefore, the gross energy demand will be decreased, as will global warming by potentially 15-70%. Also, lower demand for new batteries will reduce the need for raw materials, the environmentally harmful materials extraction process, water for mining, CO₂ emission and electricity for cell fabrication.

Challenges of Second Life Batteries

Notwithstanding the potentials advantages of the SLB, the implementation needs to overcome some obstacles and challenges:

Regarding implementation, standards and automatization will speed up their industrialization, having a positive contribution in terms of safety and cost. As explained earlier, the dismantling process will require highly qualified professionals that can have an impact on the cost-benefit of SLB.

In addition, the battery comes in different shapes and forms together with different voltages and chemistries. This is a real challenge for the reconditioning process and might require additional assessment. Thus, it can further increase the reconditioning cost.

In that context, finding a similar cell and matching the good battery together is an important factor for the performance and lifespan of SLB. The commitment is that the full implementation of the SLB impacts the price of new li-ion batteries and their cost-benefit balance positively.

In addition to that, the critical challenge is to extend the life cycle of these SLB more than 5-10 years in response to what the customer may have in mind compared to new batteries.

In that sense, an ally is the accurate measurement of SOH and RUL, as advanced predictive models may give precise information about the remaining life of the cells for an SLB application.

In summary, SLB implementation could bring substantial economic and environmental benefits. However, many challenges need to be addressed first to see the real potential of SLB, especially the lack of standards as well as the optimization and the automatization of the reconditioning process.

With these challenges in mind, CIC energiGUNE is developing new methodologies combining electrochemical tests and thermal imaging to assess the SOH and RUL accurately as well as to simplify the reconditioning process. Besides, the experts of CIC energiGUNE participate in several working groups related to standards, safety, second life, and recycling. This expertise is made available to our partner companies in various projects to make SLB a sustainable reality.