Batteries have been a hot topic for years amid the energy transition rush of many governments, but now, it has become even hotter as the search for alternatives to traditional energy becomes frantic. While lithium continues to dominate in both EVs and storage, rivals are emerging, and one of these is, essentially table salt.

Earlier this month, Chinese media reported that the first truck with a sodium-ion battery had been delivered to the mine where it will be used. The battery has a capacity of 676 kWh, a report by Car News China said, and an energy density of 165 Wh/kg. The maker of the system, a company called Hina Battery, also boasted that its battery can be recharged in between 20 and 25 minutes.

Meanwhile, U.S. companies are also developing sodium-ion batteries with a view to not only coming up with an alternative to lithium-ion technology but making this alternative independent of China-dominated supply chains. In a report about such batteries this week, the Wall Street Journal’s tech columnist Christopher Mims called them “China-free” and said that the technology “has the potential to help every country on earth break its dependence on China for batteries, and the critical minerals that go into them.”

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As is usual with battery breakthrough reports, however, the enthusiasm may be a bit premature. Sodium-ion battery technology is still relatively new and has flaws. One big flaw is energy density, as noted in a recent report in PV Magazine about progress in the field. They also have a shorter life than lithium-ion batteries. Both these flaws are related to the use of sodium instead of lithium. Sodium, the report explained, has a larger ionic radius, which “places greater mechanical stress on electrode materials and can accelerate degradation.”

These flaws are the reason why the Wall Street Journal’s Mims wrote about sodium-ion batteries “potentially” replacing lithium-ion technology. The promise is there, but first, the flaws need to be eliminated or minimized. The Car News China report about the sodium-ion mining truck noted that the battery could last for 8,000 charge-recharge cycles, saying that this was comparable to the average lifespan of a regular mining truck. So, it is China again that is making progress in alternatives to lithium-ion technology.

This is not to say that elsewhere progress is absent. The WJ article featured one startup that is eyeing a piece of the utility-scale battery storage market in the United States, currently dominated by Tesla. The company, Peak Energy, is betting on potentially cheaper, more reliable and less easily combustible batteries, the report said, noting one of the most dangerous flaws of lithium-ion systems: the risk of thermal runaway.

Other companies in the United States are also developing their own sodium-ion batteries to offer an alternative to the dominant battery tech, suggesting that there is a perception of strong demand for such alternatives. Much of that perception appears to be linked to the proliferation of data centers across the country. This, of course, has to do with data centers’ need for a reliable electricity supply at all times, combined with their ambition to use low-carbon energy. There is also the matter of grid connection delays, which are driving data center operators to turn to on-site solar plus storage to get the electricity faster, PV Magazine again reported this month.

Cracking the battery problem and developing batteries that are simultaneously reliable, long-lasting, cheap, and safe has eluded the tech industry for years. Nevertheless, progress is being made, and alternative battery technology is challenging the dominance of lithium-ion systems, little by little. It will probably be a while yet before this challenge threatens that dominance—if ever—but technological diversification in batteries is always a good idea.

By: Irina Slav