Once the final frontier, space is now a hive of activity driven by a growing demand for satellites which are ever-shrinking in size, for example nanosatellites, and the technology that goes into them, including powerful lightweight batteries. By 2023, it has been predicted that over 700 nanosatellites could be launched worldwide, up from just 88, 10 years earlier.
Miniaturisation, standardisation and cost are key to capturing this growing ‘nanosat’ sector where small changes in efficiency and weight can save on launch costs currently averaging around EUR 50 000 per kilogram.
‘Energy storage is crucial to making small improvements in the way these tiny satellites perform and what they can do,’ says Miguel Muñoz-Márquez of CIC energiGUNE in Spain. The centre led the EU-backed MONBASA project and coordinated the efforts of its three partners, the Spanish research centre Tecnalia, Gencoa Ltd (UK) and Nanospace (Sweden).
The consortium wasted no time developing novel solutions to this energy-storage gap, putting Europe back in the running for a leading role in this multi-billion-euro sector.
To be competitive, MONBASA’s technology had to meet exacting demands: highly energy efficient, lightweight, reliable, cost-effective and compliant with existing standards and regulations.
That was asking a lot, but the successful partnership delivered powerful results, among them a ‘magnetron sputtering’ technique and equipment to produce battery materials which mimic those in the latest electronic screens (i.e. plasma and OLED). These are gaining traction in both space and non-space sectors.
‘Our solution takes advantage of new processing methods widely used in microelectronic screens, smart windows, optical coatings for car screens, and so on,’ notes Muñoz-Márquez.
The batteries being developed obviously need to be nanoscale like the satellites they are designed to fit into. On an atomic level, he explains, the sputtering uses inert gases in the same way as a neon fluorescent light tube does to create a plasma where the gas atoms become positively charged. The charged atoms are delivered at high speed against a target which contains the source material to be deposited. Upon collision, these charged atoms remove tiny particles from the target source as it crosses the sputtering ‘process chamber’ and finally ends up in a ‘substrate’ where the thin film starts to grow.
While the work has focused on space applications, these pill-sized batteries are found in everything from pacemakers to car wireless sensors. A high-voltage thin-film battery based on a type of liquid electrolyte – ionic conducting solution – has been developed and prototyped. This is the starting point for future solid-state, high-voltage thin-film batteries. To learn how rechargeable solid-state batteries work and the benefits of thin-film technology, consult AZO Materials.
The MONBASA demo, featuring the new sputtering technique and equipment, claims to outperform equivalent current-generation Li-ion batteries in terms of cycle- and lifetime. For device-makers, this could mean faster-recharging, longer-lasting batteries, fewer failures and thus more durable satellites. This could potentially result in less space junk, reduced risk of collisions and improved safety in space.
Wide and long-lasting impact
While battery producers are the main target, the technical solutions developed during the project implementation phase can be used in any industrial process combining complex oxides and thin-film battery components, such as wearable objects and ‘Internet of Things’ applications that connect objects to each other and the web.
Thanks to the way the consortium was put together, it was able to rapidly take the basic research to full demonstrator ahead of industry take-up and scale-up. The potential market for MONBASA’s solutions, beyond the aero-space sector, is hard to determine, as are the potential cost savings, but general market indicators are very strong. The solid-state thin-film battery market is forecast to reach USD 1.3 billion (EUR 1.15 bn) by 2021, led by growing demand for applications in everything from medical devices monitoring glucose levels to networked vehicle tyre pressure and temperature sensors. The work places Europe in a strong competitive position to capture a good slice of this market, according to the team.
In fact, the project is already reporting significant interest from medical device-makers in high-voltage (>4 V) solid-state micro-batteries that can be shaped into ever-smaller housings and remain stable. These are very similar requirements to those in space, where a leak in a conventional liquid-based battery can ruin very expensive equipment.
‘We may have started with satellite and space technology in mind, but of course it is back on land where the big battery-makers are mostly competing, and they welcome any new method to save costs,’ says Muñoz-Márquez. ‘We don’t have a crystal ball on how much we can shave off the total cost, but we’re sure we will be competitive!’
The team also predicts wider long-term benefits to European expertise and policymaking in tailored energy solutions and tighter links between space and non-space sectors