Electric vehicles (EVs) are an important part of meeting global goals on climate change as we replace dirty fossil fuels, but with more than half of their emissions to come in the manufacturing phase, product duration is key to ensuring EVs remain low-carbon emitters.
New R&D from Liverpool John Moores University and its partners in Japan and Malaysia aims to extend the lifespan of EV electronics by creating a new solder through the addition of microalloying elements and nanoparticles.
Early results indicate the idea slows down the degradation of solder during use, reducing cracks over a products lifetime that cause solder joints to fail, so makes the solder joints more reliable, enabling electronics and vehicles to last longer.
“Everyone is advocating EVs but we still have a growing need in reliability for long term survivability,” explained David Harvey, Emeritus Professor of Electronic Engineering at LJMU. “The weakest link for these electronics devices are usually the solder interconnects.”
Phase out toxic lead
Lead, has traditionally been the base metal of solder but, due to its toxicity, is nearly phased out by global legislation such as The Restriction of Hazardous Substances (RoHS) Directive 2002/95/EC, and the EU’s Waste of Electrical and Electronic Equipment (WEEE) Directive 2012/19/EU.
Its most common replacement – an alloy of Tin, Silver and Copper – currently presents a big technical challenge in power-electronics products due to the high operation temperature in EVs.
“What we’re working on is a lead-free solder that doesn't degrade under high temperature by adding nanoparticles and micro-alloying,” said Dr Ming Zhang, lead researcher at LJMU’s General Engineering Research Institute. “The new materials should be more resistant to cracking over a products lifetime operating in a harsh environment, enabling longer lifetimes and impacting significantly a reduction in energy and materials required for product manufacture.”
“Current alloys are prone to the formation of brittle intermetallic compounds which limit the reliability of solder joints. Our initial solution is to refine their microstructure by adding minor microalloying elements and nanoparticles, enhancing the properties of solder and reliability of solder joints.”
The British Council COP26
The research is a collaborative project with Gunma University (Japan) and Universiti Malaysia Perlis (Malaysia) and is one of only four projects currently funded through The British Council’s COP26 Trilateral Research Initiative 2021-22.
Entitled Go-GREEN: Next Generation Solder Materials for Power Electronics and Green Electric Transport, the British Council project aims to establish research collaborations in the field of climate change between the UK, Japan and countries in the ASEAN territory, such as Malaysia. By 2030, Malaysia aims to achieve 100% energy efficient vehicles (EEV) - which includes fuel efficient vehicles, hybrid and electric vehicles.
An on-line workshop hosted by the Malaysian partner was attended by nearly 200 delegates from industry and academia. A further roundtable, hosted by British Ambassador to Japan Julia Longbottom, will be held on 27 October. Register at: https://www.britishcouncil.jp/en/events/innovative-approaches-collaborative-research-uk-japan-asean-initiative.
IMAGE: Post-doctoral researcher Dr Teresa Partida; Professor Ndy Ekere, Pro Vice-Chancellor Faculty of Engineering and Technology; Professor David Harvey and Dr Ming Zhang outside the LJMU engineering laboratories.