Soni-Laser Project

Project Details

10018077 : Soni-Laser – Ultrasonic assisted laser welding for high volume assembly of automotive battery packs.

EV sales will reach 44 million vehicles per year by 2030 with many European countries, including the UK, aiming at zero emissions within the next 30 years. Therefore, there is an increasing need for manufacturing of battery packs to meet demand and whilst Asia remains the stronghold (projected to reach 800GWh by 2025), Europe is expanding rapidly with a projected production capacity of 450GWh/year by 2030.

Laser welding has emerged as a very strong contending welding technique to respond to the increasing demand for EV battery manufacturing, being 4-5 times faster than the current welding processes, but challenges to its application remain.

Why laser welding?

Laser welding is a fusion process which means that both substrates being welded, melt during the laser welding process. Although the process is extremely fast, so the total heat input can be kept at low levels, there is the potential for the formation of brittle, high-resistance intermetallic compounds, especially when dissimilar materials are welded. Dissimilar joints, such as the aluminium-copper combination often found in batteries, are particularly prone to the formation of intermetallic compounds. These compounds have been shown to have a negative impact on the short-term electrical performance as well as the long-term mechanical performance of the joints in lithium batteries. Such adverse effects currently pose an industrial challenge for the automotive battery system manufacturing sector.

What is the Soni-Laser project aim?

Soni-Laser will introduce a non-contact Power-Ultrasonic Vibration Treatment (PUVT) subsystem that will assist the laser welding process of EV batteries and enhance the integrity and quality of welds. The PUVT subsystem will include both hardware -- power ultrasonic transducers -- and software -- computational models that will control process parameters such as ultrasonic frequencies. Using suitable power ultrasonic frequencies, not only can the intermetallic be redistributed, but also the weld geometry can be modified to suit the particular joint requirements.

The Soni-Laser solution will:

  1. Reduce residual stresses, along with a 10% improvement in mechanical properties (e.g. strength) of the battery weld, due to grain refinement and phase distribution;
  2. Prevent and minimise the formation of bulk intermetallics by 30%;
  3. Increase the laser welding speed by at least 50%. Commercially, Soni-Laser will be a retrofittable bespoke solution, comprising the proposed PUVT subsystem and its optimisation models, customised to each client (EV battery manufacturers) and each battery module segment within their production line.

Project Aims

  • Improvement to the mechanical and electrical connection using PUVT.
  • 30% mitigation of intermetallic compounds reducing brittleness
  • At least 10% increase in mechanical strength increasing durability
  • At least a 50% increase in welding speed enabling a 10-15% improvement in total battery productivity

Project Milestones

Ref Title WP Responsibilty Due Date Actual Date Comments
M1 Soni-Laser kick off meeting 1 Carrs February 2022 February 2022 Completed
M2 Soni-Laser requirement specifications established   2 Carrs April 2022 April 2022 Completed
M3 Development of PUVT systems 3 BUL October 2022 October 2022 Completed
M4 Soni-Laser system successfully integrated    4 Carrs May 2023 May 2023 Completed
M5 Soni-Laser system demonstrated via the CARRS’ validated test rig     5 Carrs July 2023 July 2023 Completed
M6 Soni-Laser market assessment and IP protection strategy finalised     6 Carrs July 2023 July 2023 Completed

Soni-Laser Project Reference: 10018077

Inovate UK
Innovate UK is the UK’s innovation agency

Innovate UK is an executive non-departmental public body, sponsored by the Department for Business, Energy & Industrial Strategy.