Why fast charging is the key to the electrification of mining trucks

Switching a mining haul truck from diesel to electric reduces its total cost of ownership by $2.5 million, breaking even in just 3 years [1]. This is primarily due to the significant savings in fuel and maintenance costs, which far outweigh the upfront expenditure of the battery, making electrification a more cost effective and sustainable solution for the mining industry.

As impressive as these statistics are, mining companies remain hesitant to the adoption EVs. Why? Well, productivity is the priority in mining, so it is crucial that machinery operates as efficiently as possible, 24 hours a day, 7 days a week.

Conventional battery chemistries mean that a typical 150-tonne EV haul truck needs to recharge 3 to 5 times a day, for 2 to 3 hours. Whereas a diesel haul truck only needs to refuel once a day, for 10 to 20 minutes [2].

So, it's currently impossible for an EV haul truck to match the productivity of its diesel rival, which is why mining companies are reluctant to switch to electrification.

The fast charging approach

One strategy to cut these long recharge times is to utilise fast charging technology. "Fast charging typically involves c-rates of 3C compared to 1C for standard charging in traditional li-ion cells," explains Jean de La Verpilliere , CEO at Echion.

"Mining trucks ideally require a minimum rate of 5C, this means the battery can fully recharge in under 12 minutes which is now achievable with XNO? technology," continues Verpilliere. "Not only does this drastically reduce downtime, but also the size and weight of the battery."

Of course, smaller batteries need to be recharged more frequently and although fast charging reduces this time loss, recharging still disrupts the operation of the truck. "To mitigate this, trucks can take advantage of opportunity charging," says Verpilliere. "Instead of waiting for the battery to fully discharge, you can fast charge the battery whenever is convenient. By utilising the natural downtime opportunities throughout the day, the runtime of the battery can be extended with minimal disruption."

The need for better batteries

So, why is fast charging not fully integrated into the mining sector yet?

Well, fast charging causes several issues for standard battery chemistries such as lithium-ion cells with LTO or graphite based anodes. The high voltages required to fast charge a battery can degrade these anode materials, reducing the battery’s capacity, life and safety.

However, Echion’s innovative XNO? niobium based anode material avoids these issues. It features an open crystal microstructure which allows lithium ions to quickly and uniformly diffuse into its surface, minimising degradation.

Consequently, lithium-ion cells using XNO? anodes are chemically stable, last over 10,000 charge cycles and are extremely safe. In fact, a recent study in Echion’s lab showed that XNO? retained 80% capacity after 5,000 cycles, compared to standard lithium-ion cells that retain 80% capacity after only 2,000 cycles [3]. That’s over double the cycle life!

"Fast charging only works if it is combined with batteries that can achieve high cycle life", concludes Verpilliere. "Our XNO? niobium-based anode materials allow lithium-ion batteries to fast charge quickly, safely and with minimal degradation. This is the key to unlocking electrification for the mining industry and is now possible with Echion’s XNO? anode materials."

Do you think fast charging will accelerate electrification in the mining industry? Share your thoughts below. ??

References

[1] P.J., 2024. Why Electric Haul Trucks Will Be a Success [Online]. IDTechEx [Link to: https://www.idtechex.com/en/research-article/why-electric-haul-trucks-will-be-a-success/30916]

[2] 2024. EV vs ICE Haul Trucks: Total Cost of Ownership (TCO) [Online]. IDTechEx [Link to: https://www.idtechex.com/portal.v2/pages/premium-article.asp?articleid=30504]

[3] P.A., 2024. Understanding lithium-ion battery degradation [Online]. Zitara [Link to: https://www.zitara.com/resources/lithium-ion-battery-degradation]