Slowly but surely, we have come to agree that a circular economy is the answer to our ever-growing waste problems, but when we think of sustainability, we immediately assume that recycling is the only answer and we almost forget that re-using many of our products is a critical first step before ending their usable life.
The New Gasoline
Goldman Sachs had declared Lithium as “the new Gasoline” in their equity research published in Dec 2015, yet it took companies almost five years to accelerate their race to mine lithium. As Miles O’Brien of PBS Newshour published last week, demand for lithium is growing at 20% annually for the next 20 years, and within the next 5 years 70% of that demand will be coming from electric vehicle manufacturers.
The problem is, to quote George Crabtree: “is there enough lithium in the world for 50 percent of the cars in the world to become electric, the answer is, maybe surprisingly, no. There isn't, unless you recycle.” However, “unlike lead acid batteries, there is no practical way to recycle those made of lithium” the article concludes.
To Recycle or Not To Recycle?
Chemical & Engineering News estimates that by 2020, China alone will generate around 500,000 metric tons of used Lithium-ion batteries and by 2030, the worldwide number will hit 2 million metric tons per year. “The EV industry needs to figure out its battery problem” is another article that gives you a pretty grim image of the status quo.
If you believe recycling those batteries is still a much better solution than throwing them to waste, I do agree; however we need to remember that recycling Lithium-ion batteries too soon (assuming we found a practical way to do so) is also a waste in itself if they still have a usable life.
The million dollar question is: how can we tell if those batteries are still usable or not?
You probably already know this: when you charge your new iPhone to 100% State of Charge (SoC), it’s not the same as the 100% SoC you get after using your phone for 3 years. That’s because the health of your iPhone’s Li-ion battery degrades over time with use and exposure to different conditions.
The same happens to your EV batteries (EVB): a new Tesla’s 100% SoC is not the same as the 100% SoC you get after driving and using up your EVB for 5 years, and so on. For example, a 70 kWh battery that has 90% SoH would actually act like a 63 kWh battery.
If you’re interested to see more about this, GeoTab has collected data from over 6,000 EVs and developed their “EV Battery Degradation Comparison Tool” - you can select make and model and play with the simulation here.
Naturally, we are better off recycling (or even throwing away) an EVB instead of posing a risk to drivers’ lives on the road with a low battery State of Health. However, we need to remember that an EVB’s warranty lasts for 8 years/100,000 miles!
EVB Warranties: Too Long or Too Short?
To clarify: this is only the EV’s Battery Warranty (not overall vehicle warranty). It’s a federal requirement in the US for an EV to have a separate warranty only for its battery; the most expensive component of the vehicle.
Consider the case of purchasing a Certified Pre-Owned EV (CPO): you can get an extended-warranty for your EV, but NOT for the battery: the battery warranty remains under the original one provided by the manufacturer and is not renewed or extended.
Not surprisingly, auto manufacturers are confident about that warranty coverage because “EV and hybrid batteries are lasting longer than automakers originally expected, so there’s no need to worry about the longevity of a used EV’s battery” as Annie White wrote two months ago. Also, Tesla recently announced that they’re making a battery that will last for a million miles!
This all supports the fact that Lithium-ion batteries, specifically those in EVs, have a much longer life than they’re currently used for; hence it’s equally wasteful to send them directly to waste or material-recovery recycling very early in their life.
Second Life Conundrum
The aforementioned inefficiencies enabled the creation of a niche market for 2nd life battery use cases where healthy Li-ion batteries are used in applications like Energy Storage Systems (ESS) in their 2nd life.
The problem is: how do you know if a battery is still healthy? And just “how much” health is left in it?
The current mechanism to estimate a battery’s health is by using what’s known as “battery cyclers” where you spend several hours in a labor and energy-intensive task to get an “estimated” SoH of each battery. If you incorporate the demand growth mentioned earlier, battery cyclers quickly become too expensive and not scalable.
This leaves us with a conundrum: we have so many EVBs that we “think” can be used in 2nd life applications, but there’s no affordable and scalable way of getting their SoH; so we’re better off going back to square one and sending them for material-recovery recycling (or just wasting them) than to burn more money in these 2nd life applications.
Ultrasound: A Quest for The Ultimate Battery Answer
Our conundrum led to the emergence of a breakthrough solution: using Ultrasound to accurately (and quickly) measure a battery’s SoH.
Companies like Titan Advanced Energy Solutions are dominating this niche to address the inefficient use of Lithium-ion batteries and give EVBs a useful and scalable second life in the ESS market.Titan’s patented technology works through a portable device called Scorpion which uses ultrasound pulses to measure the accurate SoH within a few seconds.
Solutions like Scorpion are potentially game-changers, allowing for a better transition of a battery’s life from their OEMs to EVs to ESS and eventually to material recovery and grinders, easily measuring the battery’s SoH locally, at any point along the way, any time, with minimal energy and effort.
This also potentially prevents safety risks of fire because ultrasound signals cannot bounce back when there’s a problem with the battery (e.g. dendrite growth, lithium plating, manufacturing inconsistencies or outgassing), hence allowing for early detection of such problems in Li-ion batteries before there’s a major risk imminent.
Clean and Sustainable Energy At Last
Expanding the use cases of energy storage systems is critical to solve yet another problem: the intermittency of clean energy sources such as wind and solar.
Storing energy generated by solar panels and wind turbines in ESS to be used on-demand could help expedite the transition from the traditional grid to cleaner energy sources that are sustainable with the availability of affordable energy storage systems. I say affordable because current ESS use new batteries that render the entire system very expensive, as opposed to 2nd life batteries with good SoH that are less pricey.
This all sounds amazing, right?
The Challenges Ahead
In practice: just where do you get so many used EVBs from, get them Scorpion-certified, categorize and match them according to their SoH and ship them to ESS manufacturers that use 2nd life batteries?
Also, if EV auto manufacturers are giving their Li-ion batteries 8 years/100,000 miles of warranty (or a million miles, as Elon Musk boasts), taking those batteries out of their EV application will immediately void that warranty. How will 2nd life ESS manufacturers create new warranties for those used EVBs? And how will insurance work in this case?
Most importantly, how will these batteries be tracked, collected and shipped around between OEMs, 1st life, 2nd life uses, and finally off for material-recovery?
There are so many more questions yet to be answered, but at least one thing is for sure: now we have the ability to know the State of Health of Lithium-ion batteries quickly, accurately, and efficiently, what we do about this valuable information is going to shape our future in mobility, clean energy and waste management, and it is up to the disruptive players in those industries to answer those challenges.