JAXA, Hitachi to Test All-solid-state Lithium-ion Batteries in Space

Hitachi all solid state lithium ion battery. (Credit: Hitachi)

TOKYO (JAXA PR) — Japan Aerospace Exploration Agency (President: Hiroshi Yamakawa, JAXA) and Hitachi Shipbuilding Co., Ltd. (President and COO: Yoshio Mino) are the world’s first all-solid-state lithium-ion batteries in space. We have signed a joint research agreement on demonstration experiments for the practical application of the batteries.

JAXA and have been jointly developing all-solid-state lithium-ion batteries since 2016 under the framework of the open call for research proposals of the Japan Aerospace Exploration Innovation Hub ( *1). All-solid-state lithium-ion batteries are attracting attention as the favorite of next-generation batteries, and are expected to be installed in various devices.

Conventionally, lithium-ion batteries used in space are difficult to use in a harsh space environment where there is a large difference in temperature and vacuum due to the fact that liquids are used and the operating temperature range is narrow. It is installed inside the equipment such as, and is used while controlling the temperature.

For this reason, we have jointly studied and developed prototypes with the aim of realizing an all-solid-state lithium-ion battery that can be used even in vacuum conditions and in harsh high and low temperature environments. Both sides will conduct a demonstration experiment in orbit to evaluate and verify the prototype battery in the actual space environment.

In the demonstration experiment, the small outboard payload support device (SPySE) (*2) on the medium-sized exposure experiment adapter (i-SEEP) installed on the outboard experiment platform of the “Kibo” Japanese Experiment Module on the International Space Station (ISS) ), Install an all-solid-state lithium-ion battery and check if the all-solid-state lithium-ion battery can operate in a harsh environment.

i-SEEP / SPySE external view and all-solid-state battery installation location. (Credit: JAXA)

In the future, we plan to develop the equipment necessary for space demonstration of all-solid-state batteries, conduct verification tests, etc., launch it for the ISS after the fall of 2021, and conduct demonstration experiments for about half a year from the end of 2021.

By using an all-solid-state lithium-ion battery, temperature control is not required, which makes it possible to contribute to reducing the size and weight of equipment used in the space environment and reducing power consumption. Furthermore, it can be expected to be used in the lunar and Mars spacecraft, which is a harsher temperature environment, and rover and observation equipment, which are mobility that operates on the lunar surface.

Overview of the all-solid-state lithium-ion battery used in this demonstration experiment

Based on the one developed by Hitachi Shipbuilding in 2016, we will use the all-solid-state lithium-ion battery jointly researched and developed by JAXA and Hitachi Shipbuilding.

Size: 65 mm x 52 mm x 2.7 mm
Quality: 25 g

Capacity: 140 mAh (15 cells will be connected in parallel to provide a power supply of approximately 2.1 Ah)

Features:

(1) Since a solid electrolyte is used, it does not solidify at low temperatures, and since the solid electrolyte does not decompose even at high temperatures, stable operation is possible even in an environment of -40 ° C to 120 ° C.

(2) Since no liquid material is used, there is no liquid leakage, and since the solid electrolyte is flame-retardant, there is no risk of ignition, smoke, or explosion.

(3) A battery configuration with minimal volatile components has been realized, and there is almost no expansion even under vacuum.

* 1 In the “Innovation Hub Construction Support Project” entrusted by JAXA from the Japan Science and Technology Agency (open innovation hub for expanding the living sphere and activity area of ​​human beings by developing the frontier of the solar system), “All-solid-state lithium-ion battery” A contract was signed in 2016 to jointly develop the next battery.

* 2 An experimental infrastructure that JAXA has been developing with the aim of diversifying and expanding the use of the medium-sized exposure experiment adapter (i-SEEP) installed on the outboard experiment platform of the Japanese Experiment Module “Kibo” on the ISS. It can be mounted on one side of the i-SEEP device mounting area to provide an interface that allows up to eight small devices (area 10 cm square, height 30 cm) to be shared. JAXA will also verify the function of SPySE by installing an all-solid-state battery.