Giving EV Batteries a Second Life

Electronic devices and gadgets are our lifelines today, from serving espresso or latte every morning to playing meditative tones to calm our nerves for a good night’s sleep. Yet, we give up on them for their latest version with added features. This is why the 40 million tons of electronic waste generated annually is comparable to throwing 800 laptops every second. Production of these electronic goods has a significant carbon footprint and accounts for about 80% of emissions produced during their total life. Legislative organizations are setting up net zero gas emission targets to combat climate change and its impact in the next 10 to 20 years. Consequently, stakeholders are obliged to transition to clean energy sources, and electrification is a step toward achieving the target. Today, with the roads flooded with electric vehicles worldwide, it is on us to give EV batteries a second life, which would count as an effort to reduce e-waste and achieve the net zero emission targets set by policymakers.

Why Second-hand EV Batteries?

The afterthought of the surging number of EVS is the afterlife of the EV batteries. There are three possible options – disposal, recycling, or reuse. Which one to choose? With limited recycling infrastructure in economically developing nations, one could either dispose of or reuse the batteries. After these batteries have reached their end-life in EVs, they will likely retain two-thirds of their storage capacity and can be used as energy storage devices for another 5 to 8 years. Especially in remote locations or grids that use intermittent energy sources for electricity supply. They could also be used in EV charging booths. It is important to note that not all second-hand EV batteries can be used for secondary applications.

The battery performance of second-hand batteries requires evaluation for further utilization. The rapid charge-discharge cycles, thermal degradation, and usage to maximum storage capacity are a few aspects to consider. Moreover, a few challenges must be intervened before used-EV batteries can be commercialized as energy storage devices. As EV production increases at an unprecedented rate, battery prices are expected to decline. Over time, there will be a negligible price difference between used and new EV batteries, which would reduce the value of the former. At the same time, the ultimate goal is to maintain a sufficient price difference so that there are markets for both battery types.

In today’s market, every EV manufacturer has their own set of battery models, making it difficult to accumulate a standardized set for second-hand applications. If there are 15 new models of EVs, there are 15 different battery models. Stacking these different battery models together is difficult for utility-scale energy usage, especially with the wiring, material composition, etc. Hence, it is highly recommended to standardize EV batteries, not just for second-hand applications but also to come in handy while recycling materials such as nickel, lithium, and cobalt to make new batteries.

Evaluate and Extend Second-hand Battery Performance

As a stakeholder in this market, there are a few techniques to help evaluate the performance of second-hand EV batteries, which includes

• 1D and 3D CFD simulation – Using 1D CFD simulation, the thermal performance of the entire battery pack can be studied with comparatively less computational power. Any irregularities in the behavior of a specific component in the pack can be tracked for further evaluation. This is where the 3D CFD solutions come nifty. Specific components can be evaluated for pressure drop, velocity, and heat transfer, to ensure optimum operating temperatures for their best performance. The impeccable speed at which different design ideas can be modeled and analyzed puts CFD technology under the spotlight.
• Onboard battery diagnostics – EVs should have built-in battery diagnostic capabilities to provide insights into the battery's health for second-hand users. Further, it is also possible to install battery diagnostic systems onto used batteries to study the performance fluctuations and temperature degradation for early remediation. Few of the battery diagnostic tools available in the market use battery control algorithms to extend the battery life using cell-actuation circuitry. Cloud-based battery management systems that use AI to get real-time battery performance data and predictive analytics are also beneficial.

Cadence Fidelity CFD provides a robust, easy-to-use framework for analyzing and simulating all-electric components from geometry preparation to dedicated post-processing. With significantly reduced engineering and CPU time, thanks to the fastest solvers and highly automated workflows, engineers can focus more on the design challenges of new mobility solutions.

** Guitarist Robot - Deutsches Museum

    BMW Isetta EV - BMW Welt

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