What actually happens to old EV batteries?

Like all batteries, those in EVs degrade over time, and eventually are unable to hold the driving range necessary to make them useful in the vehicle. 

One of the long-standing questions then becomes, what happens to these batteries when they can’t be used in cars anymore? Are they just e-waste? 

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The consequence of potentially throwing out batteries gives rise to well-documented issues of toxic wastes associated with battery technology. 

These issues become more poignant as the electric car industry expands rapidly, with more EVs hitting the roads, and their batteries degrading. 

Recycling is proving the most advanced reprieve to such issues so far. 

In 2021, Injectronics, a Melbourne-based firm, now known as Infinitev, announced a hybrid battery remanufacturing exchange program for some Toyota hybrid models. 

Infinitev is a subsidiary of Innovative Mechatronics Group, a company specialising automotive electronics and mechatronics.

The scheme only applied to models with Nickel-Metal-Hydride (NiMH) batteries, which reside in Toyota Prius, Camry and Corolla variants.

The process involves testing each battery cell to identify which ones are failing. Individual cell testing ensures that only the faulty cells need to be replaced as opposed to the whole unit being thrown away.

This refurbishment process offers owners significant savings compared to buying a new battery.

When it comes to the much larger batteries in electric cars though, different brands use different types of batteries, which have different levels of viability for recycling. 

For example, lithium-iron-phosphate (LFP) batteries are less recyclable than other batteries, despite being increasingly popular due to their lower cost while maintaining good energy density and a long life cycle. 

They lack the economic viability to be recycled because they contain less hard-to-source materials, reducing the incentives for recycling. 

Nickel-magnesium-cobalt (NMC) batteries are another type of lithium-iron battery used in many higher-end or higher-performance EVs.

Unlike LFP batteries, NMC batteries are more likely to be recycled as they contain rarer metals, which are expensive to acquire.

This makes Nissan’s latest initiative for its Leaf EV NMC batteries all the more interesting.

The brand plans to use recycled Leaf batteries to power part of its Nissan part manufacturing plant in Victoria.

Differing from Injectronic’s Toyota initiative, the batteries are not refurbished and put back into cars, but are used for a different purpose - to power part of a factory. 

The nine recycled first-generation Leaf batteries will be charged using the solar system at the factory, and will power equipment such as new EV chargers to recharge staff vehicles. 

This is because tasks such as powering lower-voltage equipment are not as intensive as providing driving range to a car, and yet even with battery degradation, these batteries can still store enough capacity from the grid or a solar array to power an entire household for days, fully charge a plug-in hybrid, or partially charge another EV.

Programs such as Nissan’s can prolong the life of a battery that would otherwise be considered waste, unable to work for its original purpose.

Nissan said it estimates it will reduce emissions for the part factory by 259 tons of C02 and save 128 megawatts of energy every year. 

Nissan is not the only brand on the front foot with battery recycling, BMW is involved in repurposing old i3 batteries for second life applications, or in an Australian partnership, shredding the batteries in such a way that the valuable materials can be recovered and re-used.