Regenerative Deep Discharge:

Written By Anthony Ferrando

A SUSTAINABLE, SAFE AND EFFICIENT APPROACH TO LITHIUM BATTERY RECYCLING

These days, the rapid shift toward electrification is impossible to ignore. With electric cars quietly cruising by and charging stations popping up on nearly every corner, it’s clear that this transition has moved beyond a trend for early adopters. But have you ever wondered what happens to all these batteries when they reach the end of their lives?

The simple answer used to be: they are shredded to form black mass which is then chemically processed to extract valuable materials.

The reality is that the accelerated pace of electrification has created demand for efficient solutions to manage end-of-life batteries which continue to increase in size and capacity. Many of these batteries still contain residual energy, creating new challenges in the recycling process.

The Importance of Deep Discharging in Battery Recycling & Reverse Logistics

Lithium batteries are known for their high energy density: an attribute that makes them exceptionally powerful in use, but also potentially hazardous when it’s time to recycle.

Lithium is highly reactive, making the transport and handling of these batteries complex, dangerous and expensive. To add to this, modern EVs and Battery Energy Storage Systems (BESS) have adopted 400V and even 800V battery architectures as standard.

Without discharging them, the voltage on the terminals of these batteries as well as the residual energy inside pose significant risks for workers during dismantling and recycling, but also for capital intensive infrastructure used in these processes (shredders and intra logistics).

That is why deep discharging has become a critical first step to reduce the risks and costs associated with handling, transporting, and recycling these batteries. Deep discharging is the process in which all the electrical energy in a battery is released. When done correctly, the battery voltage is reduced to 0V, depleting any remaining energy and preventing the battery from storing any electrical charge.

However, herein lies a paradox in the battery industry: while the electrification movement and battery recycling aim to promote sustainability, most traditional deep discharge processes implemented today are quite… well: traditional. They are old-fashioned methods that scale poorly to today’s volume of batteries to be recycled. As a result, they are taxing on the environment, waste energy and contribute to pollution. 

Why Choose Regenerative Deep Discharge?
Traditional battery discharge methods typically rely on:

  • Resistive discharge, which is taxing on the environment because it wastes residual energy as heat and requires cooling to keep up with an industrial pace of discharging

  • Conductive baths, necessitating much more time to reach a partial discharge, often lead to inefficient energy dissipation, and require the disposal of polluted water streams.

Regenerative deep discharge offers a more sustainable approach with several distinct advantages:

  • Reduced Carbon Footprint: Unlike traditional methods that waste energy, regenerative deep discharge channels the energy stored in end-of-life batteries back into the power grid or facility. This process not only lowers overall energy consumption at recycling facilities but also directly reduces the carbon footprint of pretreatment operations. In other words, the energy potential of each battery can be reused rather than lost.

  • Lower Operational Costs: Recycling facilities benefit from reduced energy expenses by reclaiming energy from batteries rather than relying entirely on grid power. Over time, this can result in significant cost savings, particularly for large-scale operations processing thousands of batteries.

  • Efficiency and Productivity Gains: Regenerative discharge provides greater control over key parameters, such as power, current, and temperature limits, while also allowing for the collection of valuable data from discharge curves. This solid experimental data minimizes risks and facilitates discharging at optimal power rates. Ultimately, this enhanced control enables informed decisions for process optimization, reducing discharge times per battery.

Summarized, regenerative discharge minimizes waste associated with battery recycling and enables an optimal recovery rate of critical materials and energy. This represents crucial opportunities for the reverse logistics industry overall:

Regenerative Discharge as a Key Step in Reverse Logistics

From a reverse logistics perspective, deep discharge serves as a foundational element in safely storing and transporting lithium batteries through each recycling stage. Reverse logistics aims to optimize every aspect of the journey from end-of-life products to raw materials ready for reuse. By adopting regenerative discharge, facilities create an operationally safer and more streamlined recycling flow, which directly contributes to the broader circular economy.

As facilities worldwide strive to enhance their environmental performance, adopting regenerative deep discharge has become a powerful tool in reaching this objective.

Conclusion: Regenerative Deep Discharge – Solving the Industry's Sustainability Paradox

In this post we’ve briefly introduced the high level challenges to be solved in the battery recycling industry.

Keep an eye on our LinkedIn profile and website for future posts, in which we’ll explore the specifics of various discharge methods more in-depth and why regenerative technology offers unmatched benefits for today’s recycling facilities. If you have any questions or would like to see a particular topic covered in our future posts, please don’t hesitate to reach out!

Anthony Ferrando