TOKYO -- Imagine electric cars that can travel 700km to 800km on a single charge, twice as far as they do today. Imagine batteries that are smaller, safer and pack more punch than the lithium-ion cells that power our gadgets now.
Such is the promise of solid-state batteries. Capable of holding more electricity and recharging more quickly than their lithium-ion counterparts, they could do to lithium-ion power cells what transistors did to vacuum tubes: render them obsolete.
As their name implies, solid-state batteries use solid rather than liquid materials as an electrolyte. That is the stuff through which ions pass as they move between the poles of a battery as it is charged and discharged. Because they do not leak or give off flammable vapor, as lithium-ion batteries are prone to, solid-state batteries are safer. They are also more energy-dense and thus more compact.
Solid-state batteries are a promising power source for the internet-of-things devices that are coming into wider use, and for electric cars because of their potential to offer greater range than the stacks of lithium-ion cells that power such vehicles now.
Last December, TDK began shipping samples of CeraCharge, a solid-state battery measuring just 4.5mm by 3.2mm by 1.1mm -- smaller than a grain of rice. The Japanese company says it can turn out up to 30,000 a month. "It is the world's first instance of practical application for a solid-state battery that can be incorporated into electric circuits," according to a TDK representative.
TDK developed CeraCharge as a replacement for coin cell batteries. As the internet of things develops, demand for tiny, inexpensive batteries to power web-enabled devices is growing. Because CeraCharge batteries are so small, they allow greater flexibility in designing circuits, said Masahiro Oishi, who led the team that developed the product.
CeraCharge cells use a lithium-based ceramic oxide as the electrolyte, which is layered into a battery pack. TDK says the product maintains its performance in high- and low-temperature environments. Similar products designed for use in internet-of-things devices are also being developed by other Japanese companies, including Murata Manufacturing and Taiyo Yuden.
The battery makers' biggest prize is the market for electric cars. Bloomberg New Energy Finance estimates sales of such cars will top 60 million by 2040.
In Japan, a collaborative effort was launched on June 15 involving the national government, industry, research organizations and academic institutions. Participants include 23 companies, such as Toyota Motor and Panasonic; 15 universities, including Tokyo Institute of Technology; and research organizations. The project aims to develop technology to make solid-state automotive batteries practical and mass-produce them.
The New Energy and Industrial Technology Development Organization, or NEDO, an agency affiliated with Japan's Ministry of Economy, Trade and Industry, is leading the effort, bringing together automakers and companies specializing in materials and battery development. It hopes to come up with designs and develop manufacturing processes and testing methods for automotive solid-state batteries by the end of March 2023.
Up to now, the drive for solid-state batteries has focused mainly on material development, said NEDO's Kei Hosoi, who heads the project. The organization aims to speed things up by bringing automakers on board.
Japanese companies, including Panasonic, were once world leaders in lithium-ion batteries. But they are feeling the heat from China as its government has pushed the development of automotive batteries, and its market has become the biggest in the world for electric cars over the past few years.
China's Contemporary Amperex Technology, or CATL, is the world largest producer of automotive batteries. It is working with Japan's Honda Motor to develop batteries for electric vehicles aimed at the Chinese market, and is set to start supplying batteries to Germany's Volkswagen.
But Japan still has the edge in solid-state batteries, with its companies holding nearly half the patents in the world for related technologies. "We're going to bring together the technological strengths of Japan, and we aim to far surpass China," said NEDO's Hosoi.
Japanese companies with key technologies include Toho Titanium, which has developed a high-output solid electrolyte that combines titanium and lanthanum, a rare-earth metal. It recently started shipping samples of the product.
Optical glass maker Ohara has developed a glass-based electrolyte.It that could have wide commercial applications, according to Nomura Securities analyst Yuji Matsumoto.
Information Technology company Fujitsu uses artificial intelligence to develop battery materials. Working with Riken, a research institute affiliated with the Japanese government, it is trying to determine the ideal composition of materials for use in solid electrolytes. Using the technology, Fujitsu hopes to accelerate the development of new materials, which typically takes more than a decade.