We Must Move Swiftly to Build Sustainable, Affordable Batteries

Homeowners and utilities need better energy storage now. But mining lithium is not the answer.

The biggest innovation story this past year wasn’t the brief, tiny fusion experiment that dominated headlines, hinting at a distant future of limitless energy. Instead, it may have been a non-polluting, high-capacity battery breakthrough that could replace lithium. More on that shortly.

A few years ago, large-scale storage of energy seemed like a limited niche, a pricey way to energize off-grid homes. But the utility landscape has fractured. Major climate events, such as the Texas freeze, along with huge spikes in natural gas prices (remember how fracking advocates promised that gas was abundant and would remain stable in price for decades?) have shaken our confidence. 

Actually, more than shaken. A perfect storm of utility privatization (leading inevitably to corruption), along with aging infrastructure has driven energy prices double digits higher in many regions. I can’t count how many desperate (or angry) posts I’ve read on my Maine neighborhood chat board about unexpected increases in gas and electricity bills. 

This lack of resilience brings the conversation back to alternate energy sources. The most logical first stop for homeowners is solar power. But photovoltaics (PV)’s weakness has always been storage. The sun doesn’t shine at night, and sourcing Btu energy for heating from batteries requires a hefty power bank.

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For most manufacturers, that means lithium. It’s a battery technology that has served us well, aside from the occasional violent explosion (there’s a reason airlines don’t want lithium batteries stored in our baggage). Mining for lithium can be nearly as polluting as extracting fossil fuels. Then there’s cost: lithium-based batteries for household solar storage can double the cost of a PV installation. 

This year, while pounding the floor of the NAHB International Builders’ Show in Las Vegas, I came up empty on battery innovations. I found lots of other energy-saving products and services—many of them highlighted in our annual awards issue—but no storage miracles. It’s a tough technical nut to crack.

However, they do exist. You have to look far and wide. For example, Research at Australia’s University of Sydney School of Chemical and Biomolecular Engineering has made major strides in optimizing a salt-based battery. They’ve built one that lasts four times longer than lithium.

To put the performance of these batteries in scientific terms, this salt-based material exhibits an unprecedented reversible capacity of 505 mAh g−1 over 1,000 cycles, with a low capacity fading rate of 0.05 percent per cycle.

What’s more, these prototype batteries could be built with easy-to-access materials, recycled with minimal negative environmental impacts.

We have hit an energy glass ceiling that we can only shatter with better, more-affordable battery storage. Let’s not invest in lithium mines and toxic metals, when tomorrow’s cleaner, more-powerful batteries are just around the corner.