What would you think about a battery that sports five times the capacity of the average lithium-ion one? And then what if this batter was cheaper, and even more environmentally friendly? This is not a hypothetical battery—it exists—and now researchers are working to make it suitable for wide adoption.
This new battery is a lithium-sulfur battery, and like any new tech, it comes with problems. The main problems are the poor conductive properties of sulfur and the instability of the chemical. The problem with Lithium isn’t new, however. Lithium can become unstable, compromising the performance of the battery. Electrode breakdown is also an issue with these otherwise promising batteries. While this may sound like too many problems, a way around them has been suggested.
A team of researchers from the University of Texas at Dallas discovered that molybdenum—a litle known metal—could solve many of these problems. Molybdenum is usually used to improve the strength and hardness of steel, but in the lithium-sulfur battery, it could be combined with sulfur to create a nano-level layer of a substance that improves the conductivity of sulfur and improves the stability of the battery.
Previously, improvements of lithium-sulfur batteries consisted of adding lithium metal to the anode and sulfur to the cathode. Yet with lithium prone to sprouting so-called dendrites, and with sulfur being too insulating, the improvements were not exactly effective. Molybdenum, apparently, can both enhance lithium’s performance on the anode, and reduce sulfur’s insulating strength on the cathode.
The discovery comes soon after another one in lithium-sulfur batteries: a polymer that can further boost the already considerable capacity of the battery. The polymer acts as a binder that regulates the flow of ions from one electrode to the other, improving the efficiency of the battery and doubling its capacity. The polymer also improves the stability of the battery, keeping it working for more than 100 charge/recharge cycles.
The implications of these advancements could be massive, and not just for the electric car industry but also for base metals. Right now, we’re witnessing a major rally in what are already collectively called battery metals. But lithium-sulfur batteries need neither nickel, nor cobalt. If progress continues to move closer to commercial adoption, it could put an end to the rally sooner than many expect.
Of course, as with all other very promising batteries, it is difficult to make any predictions about what will happen and when. Nevertheless, authors of studies into batteries are invariably optimistic. “This was what everyone was looking for, for a long time. We are taking this to the next step and will fully stabilize the material, and bring it to actual, practical commercial technology,” said one of the authors of the latest lithium-sulfur battery study.
Yet this could take years, and until then, lithium-ion will continue to reign supreme.
On the other hand, as we are wont of reminding everyone, the sheer amount of research being done into better, cheaper, more reliable batteries is bound to produce at least one viable alternative to lithium-ion technology in the not-to-distant future.