Honda Unveils Solid-State Battery Demonstration Production Line

The new demonstration line will start in January, and Honda wants to mass-produce solid-state batteries before 2030.

November 21, 2024

Sebastian Blanco

Overhead view of Honda demonstration production line for all-solid-state batteries. (Honda)

Honda Motor Co., Ltd. is taking the next step in bringing its proprietary solid-state batteries to production. The automaker unveiled its demonstration production line for all-solid-state batteries at its factory in Sakura City in Tochigi Prefecture, Japan. Honda said it will start making batteries on the demonstration line in January 2025.

Honda’s cathode roll-pressing machine at its new all-solid-state battery production site is modified from traditional li-ion battery production. (Honda)

The approximately 27,400 m2 (295,000 sq. ft.) demonstration line will help Honda meet its previously stated goal of starting mass production of solid-state batteries for electric vehicles that will hit the market before 2030. In a statement announcing the new production line, Honda said it would also use solid-state batteries in “a wide range of Honda mobility products, not only automobiles but motorcycles and aircraft. The reason, unsurprisingly, is to “further reduce battery costs by taking advantage of economies of scale.” Because the demonstration production line will be used for research and development purposes, Honda declined to provide any estimates on the total amount of batteries it hopes to produce there in the next year to SAE Media.

A view of Honda’s cell assembly process equipment at its new all-solid-state battery production line in Sakura City, Japan. (Honda)

Honda said it is “conducting speedy research and development” of solid-state batteries in two core areas: material specifications and manufacturing methods. The line falls in the latter category, as it will allow the automaker to conduct technical verification of its mass production processes, including the weighing and mixing of electrode materials, the coating and roll pressing of electrode assembly, cell formation and module assembly. The company said these verifications will help Honda with the former category, allowing engineers to determine the basic specifications of the battery cells. The verification processes can be split into sections to make it easier for Honda engineers to evaluate and improve them. Honda told SAE Media that when the time comes to construct a mass production plant, the automaker will, “likely take this design and customize it for mass production to achieve greater efficiency.”

Production time per cell should decrease at Honda’s solid-state demonstration production line because of a reduction in the bonding process between positive and negative electrodes. (Honda)

Honda has pointed out in the past that it is more challenging to make all-solid-state batteries than those with liquid electrolytes because, in part, the solid electrolyte has to be stamped to increase its density. The new production line modifies the conventional liquid li-ion battery production roll-pressing technique to increase the density of the solid electrolyte layers. By making continuous pressing possible, Honda hopes to increase the degree of interfacial contact between the electrolyte and the electrodes, which then makes it physically easy for ions to flow in the battery. Production time per cell should also decrease because of a reduction in how long it takes to bond the positive and negative electrodes.

Honda’s line was built on property belonging to Honda R&D Co., Ltd. at the Sakura City plant.

"The all-solid-state battery is an innovative technology that will be a game changer in this EV era,” said Honda R&D president Keiji Otsu in a statement. “Replacing engines that have been supporting the advancements of automobiles to date, batteries will be the key factor of electrification. We believe that the advancement of batteries will be a driving force in the transformation of Honda. Now, the start of operation of our demonstration production line for our all-solid-state batteries is in sight, and we can say that we have reached an important milestone for Honda and the country of Japan. We will continue taking on challenges to launch our mobility products equipped with our all-solid-state batteries as quickly as possible." Honda said it remains committed to its goals of carbon neutrality for all Honda products and corporate activities by 2050 and to have EVs and hydrogen fuel cell vehicles make up 100% of its new vehicle sales globally by 2040.