Research Agreement Brings All-Solid-State Lithium-Ion Batteries to Space
JAXA and Hitachi Zosen jointly research and develop a prototype of an all-solid-state lithium-ion battery and plan to run a demonstration experiment in space.
National Research and Development Agency, the Japan Aerospace Exploration Agency (JAXA), and Hitachi Zosen Corporation entered into a joint research agreement to evaluate a prototype of an all-Research Agreement Brings All-Solid-State Lithium-Ion Batteries to Space (ASSLB) in space. To commence with the demonstration experiment the prototype battery will be installed in the Small Payload Support Equipment (SPySE) on the IVA-replaceable Small Exposed Experiment Platform (i-SEEP). This will itself be installed on the Exposed Facility of the Japanese Experiment Module "Kibo" on the International Space Station (ISS).
A view from the outside of the i-SEEP/SPySE and the installation location of ASSLB. Image used courtesy of JAXA
All-Solid-State Lithium-Ion Batteries
ASSLBs are receiving great interest from manufacturers and research scientists because of their attractive qualities. Such qualities include safety, high energy, and power densities. Compared to conventional lithium-ion battery (LIB) technology, ASSLBs utilize solid-electrolytes (SEs) instead of liquid electrolytes (LEs). The LEs found in today's cutting-edge LIBs provide a narrow operating temperature range. This means that at low temperatures electrolyte conductivity and performance are reduced. At high temperatures, LEs become highly reactive, which can accelerate the decomposition and deterioration of other battery components, ultimately leading to malfunction. The high volatility and flammability of LEs can cause combustion and hazardous explosions. Research Agreement Brings All-Solid-State Lithium-Ion Batteries to Space
The SEs of ASSLBs remove this safety hazard, as they are non-flammable. SEs also serve as rigid physical barriers between the anodes and cathodes. This allows for bipolar electrode configurations, which can optimize energy density and utilize limited space for a more compact design.
An ASSLB developed by Hitachi Zosen in 2016. Image used courtesy of Hitachi Zosen
The ASSLBs that have been jointly researched and developed by JAXA and Hitachi Zosen are based on the battery developed by Hitachi Zosen in 2016. These batteries that are to be exposed to the harsh environmental conditions in space, have a mass of 25g, are 65mm×52mm×2.7mm in size, and have a capacity of 140mAh. The SEs present in the ASSLBs ensures that solidification at low temperatures does not occur and prevents decomposition. This provides stable operation within an environment of -40°C to 120°C. The batteries being used in the demonstration experiment also feature a battery configuration with microminiaturized volatile components and almost no expansion, even under vacuum.
Bringing the ASSLB to Space
Ultimately, the experiment will be conducted to consolidate whether the ASSLB can operate within the harsh conditions of space. Both JAXA and Hitachi Zosen plan to continue the development of equipment for the space demonstration experiment and conduct verification tests. ASSLBs do not need strict temperature control. This can allow for miniaturization, lightening, and reduced consumption of power for equipment used in the space environment.
JAXA and Hitachi Zosen plan to launch the equipment to the ISS in the fall of 2021 or later. From the end of 2021, the two organizations also plan to conduct demonstration tests for about six months.