Diesel is in its dying days.
HVO (Hydrotreated Vegetable Oil) is a lower carbon transition fuel for on-location power but it comes with its own sustainability issues, and with internal combustion generators phasing out, the future of production belongs to batteries.
Lithium-ion battery (LIB) technology has been the dominant battery technology of the last decade, undergoing mass adoption in a short amount of time, with continuous improvement in the technology. Lithium-ion powered cars only became readily available in the early 2010s and the batteries used today are substantially different from those used even just ten years ago.
- The Lithium Challenge
- Hot or Not?
- A Lithium Alternative
- Sodium Cell Advantages
- Preserving With Salt
- Environmental Impact
As battery power becomes more prominent in our lives, the challenges around lithium become clearer.
Mining is always environmentally devastating.
As demand grows and the world’s finite lithium resources are used up, lithium mining will bring its own set of problems.
Lithium requires a huge amount of water to extract — a major problem in a world that is increasingly water poor.
The element is also unevenly distributed around the world, putting some countries in a position of energy dominance over others when universal cheap energy is badly needed.
Additionally, the global demand for battery power as the world decarbonizes means that the supply of lithium might struggle to keep up with demand. LIBs can be recycled, particularly for their copper, cobalt, and nickel, but making use of the lithium in the recycled “black mass” is far from straightforward and still on its way to being cost-effective.
Currently, using virgin lithium is cheaper than using recycled lithium.
Safety is also a concern.
Damaged or shoddily built lithium batteries can heat up and start fires that are very difficult to extinguish and can even burn under water. While it’s true, that accidents are amplified in the news (often boosted by those with an interest in seeing low-carbon technologies fail), they require that certain safety precautions are observed, especially when units are big enough to power vehicles or used to replace on-set generators. We must classify lithium batteries as dangerous goods when shipping, which means extra cost and care — and extra paperwork — every time you move them.
This is not to scare anyone off lithium-ion power.
Safety is going to be an essential part of energy storage, and the technology is being improved all the time.
Lithium-ion phosphate batteries are a more favored alternative to LIBs — safer, lower cost, and potentially cobalt-free — but they still have a lower energy density, besides the issues accompanying lithium mining, extraction, and recycling.
But then there's sodium.
The chemistry behind sodium-ion batteries (SIBs) is roughly the same as that of lithium. Sodium and lithium occupy the same group on the periodic table. In sodium cells SIBs, sodium replaces lithium as the battery cathode. But there’s a raft of differences between sodium and lithium tech that makes sodium a good bet as a power storage option for the future.
Sodium cells were first developed around the same time as lithium. But the greater charge density of lithium — and so, longer life — pushed lithium to the forefront when portable devices were booming and time between charges became a top priority for everyone.
Sodium battery technology has continued to develop to where it is now a viable alternative to lithium, with many more advantages.
Unlike lithium, sodium is ubiquitous.
Most sodium for industrial use is obtained from mining halite (aka sodium chloride, aka table salt), the leftovers of evaporated ancient seas.
Then there are our contemporary oceans: According to the US Geological Survey, the weight of sodium chloride in one cubic mile of ocean is about 120 million tons. We aren’t likely to run out of sodium soon.
Sodium cells are chemically much less reactive than lithium cells and don’t heat up.
In a recent demonstration of different battery technologies used for film and TV production, an attending LA County firefighter said that the sodium battery on display was the only one he’d feel safe having on set.
One advantage of sodium technology is longevity.
For centuries, we have used salt for long-term preservation of everything from food to pharaohs.
That principle also seems to have an analog in battery chemistry too.
If you run a lithium battery down to zero, it typically damages the cell beyond recovery. Some small bit of energy always must be maintained in the battery for it to continue to stay functional.
Your gauge may tell you that your lithium battery charge is at zero, but the manufacturer has kept back a little extra in reserve to keep the battery alive.
But the chemistry of sodium means you can drain all the energy in a SIB sodium battery down to zero — real zero — and the cell remains undamaged. And the cell can hold its structure and not break down. There’s no reason a sodium battery can’t be charged back up to 100% again after sitting on a shelf for months, or years, or even decades.
This means that the housings of sodium cells need to be made to last if customers want to get maximum use out of them. Manufacturers will need to think about how their long lifespan and reuse potential can be best leveraged. Will we see more standardization of batteries across devices, with batteries moving on once the tech they power has fallen apart around them? Or will this be an incentive to make longer lasting or more interoperable devices that can keep pace with the new power supply?
All that sounds great.
But what’s the downside?
Lithium batteries still outpace sodium in their energy density. So, a sodium battery must be larger to have the same storage capacity. Not great when size and weight are essential considerations for battery power, especially for transport.
But sodium battery technology is getting better all the time. Given sodium’s benefits, a lot of investment is going into ironing out the bugs and making sodium batteries more and more efficient. Just in the past year, Japanese researchers have found a way of making SIBs match lithium-ion energy density with an electrode made of nanostructured hard carbon, and more improvements are no doubt on the way.
We also need to be thinking about the environmental impact of any transition to sodium batteries. The chemical ingredients in a SIB are as inert as any environmentally minded company could wish for, but we’ve been bitten on the backside repeatedly over the years, thinking we’ve found harmless solutions which, when ramped up to a planetary scale, can create problems. A few vehicles releasing harmless CO2 into the atmosphere are barely worth commenting on; 1.5 billion cars doing the same have smashed the homeostasis of an entire planet.
Already, human activity is altering the salinity of the oceans. Human-caused climate change is making salty water areas saltier and freshwater areas fresher. The salinity of water has effects on water density, temperature, and — of course — the biodiversity that has developed in those ecosystems. With sodium so cheap and easily extracted, there’s a danger that we might think of sodium batteries as disposable, with SIBs becoming the plastic shopping bags of energy.
Sodium batteries are a far more environmental technology than lithium batteries, but the ramp up in battery production ahead is going to require careful environmental monitoring no matter what the technology is. If there’s one thing the last century has taught us, it’s that there is no such thing as a free lunch with energy production — even if some lunches are much, much healthier than others.