Li-ion replacements promise improved safety, lower prices — someday
TETSUO NOZAWA, Nikkei Electronics staff writer
TOKYO — Lithium-ion batteries are in everything — smartphones, wearables, drones, electric vehicles, power system stabilizers, even jetliners.
But safer, cheaper and higher-capacity power packs are poised to replace them.
While still years away, post-Li-ion batteries are no longer stuck in the distant future.
This past year has seen a number of significant technological breakthroughs. If only one of a number of promising technologies can be commercialized, we can expect dramatic performance improvements from a host of gadgets and machines.
One alternative is the solid-state battery, which uses a solid electrolyte instead of the electrolytic solution that does the heavy lifting in transporting the positive lithium ions between the cathode and anode in today’s batteries. Researchers have succeeded in developing an efficient electrolytic solid material that significantly improves lithium ion conductance, raising hopes that batteries with much higher power densities are edging closer to reality.
Lithium-air batteries, meanwhile, have the ability to greatly improve energy density, but researchers have hit a discharge wall — these power packs can’t put out much current for very long. Yet this technology could also be on the cusp of a dramatic turn: Researchers have succeeded in raising the density close to theoretically expected levels, if only for a single charge cycle.
The need to compromise
Another breakthrough battery does not use lithium. Researchers have succeeded in creating a cathode material for the sodium-ion battery; its discharge capacity beats that of Li-ion cells. The material also enables the power packs to be recharged upward of 500 times, overcoming one of the weaknesses limiting the technology’s prospects.
Battery research has undergone a big shift in recent years. It used to be that nearly half of the presentations at the Battery Symposium in Japan were about fuel cells and Li-ion battery cathode materials. But between 2012 and 2016, the number of fuel cell presentations dropped in half; those regarding cathode materials have decreased by a third since 2012. Presentations on solid-state, lithium-air and non-Li-ion batteries increased by 50% to 100% over the same period.
Toyota Motor in recent years has been a big sponsor of the Battery Symposium in Japan. The automaker has focused on developing solid-state and Li-air batteries. At the symposium in November, the automaker discussed a scenario for transitioning from Li-ion batteries to solid-state and then Li-air batteries in its vehicles.
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