SUstainable Reversal oF metallic Adhesive Connections Tailored for Augmenting Net zero Transportation (SURFACTANT)
Lead Research Organisation:
University of Sheffield
Abstract
Proposal context
Ambitious net-zero targets and society's expectation for a continuous 'on-demand', clean, secure, and sustainable energy commodity necessitates a significant expansion in the UK's electrical infrastructure. The DfT's 2022 report "Taking Charge: the electric vehicle (EV) infrastructure strategy" and the APC's automotive battery end-of-life value chain roadmap, published in June 2023, highlight strategic economic benefits associated with this challenge. Regional and UK-wide prosperity, allied with extending battery life provides the support needed to grow a second hand EV market to allow vehicles to be more affordable, whilst simultaneously improving environmental stewardship through improved recycling and a reduction in demand for critical raw materials, further reducing energy usage.
The challenge the project addresses and how it will be applied to this:
Extending battery life through tactical replacement or repair of battery cells and / or modules provides a manifold of benefits and offers new market opportunities for the transportation sector. Presently, battery designs and those sub-assembly electrical connections between cells and busbars are created using fusion or solid-state bonded processes producing non-reversible joints; i.e., separation of joints is a destructive activity if they are to be replaced, repaired or recycled. Mechanical methods have been investigated and used for early designs, but these are vulnerable to 'efficiency drop-off' triggered by 'resistance ageing', resulting from thermal and corrosive activities between the connection interfaces and loosening of connections caused by random vibrations. The University of Sheffield, Heriot-Watt University and the University of the West of Scotland will develop a sustainable manufacturing process for battery applications, enabling assembly, non-destructive disassembly and reassembly between electrical connections to achieve full recovery of the cells and busbars.
Our EPSRC funding request brings together expertise from across multifarious engineering disciplines: surface engineering and flow dynamics; materials science; joining; AI; and tooling design. We will utilise outputs from previous EPSRC funding projects; e.g., 'NASCENT' to accelerate capability to produce a reversible solution.
Ambitious net-zero targets and society's expectation for a continuous 'on-demand', clean, secure, and sustainable energy commodity necessitates a significant expansion in the UK's electrical infrastructure. The DfT's 2022 report "Taking Charge: the electric vehicle (EV) infrastructure strategy" and the APC's automotive battery end-of-life value chain roadmap, published in June 2023, highlight strategic economic benefits associated with this challenge. Regional and UK-wide prosperity, allied with extending battery life provides the support needed to grow a second hand EV market to allow vehicles to be more affordable, whilst simultaneously improving environmental stewardship through improved recycling and a reduction in demand for critical raw materials, further reducing energy usage.
The challenge the project addresses and how it will be applied to this:
Extending battery life through tactical replacement or repair of battery cells and / or modules provides a manifold of benefits and offers new market opportunities for the transportation sector. Presently, battery designs and those sub-assembly electrical connections between cells and busbars are created using fusion or solid-state bonded processes producing non-reversible joints; i.e., separation of joints is a destructive activity if they are to be replaced, repaired or recycled. Mechanical methods have been investigated and used for early designs, but these are vulnerable to 'efficiency drop-off' triggered by 'resistance ageing', resulting from thermal and corrosive activities between the connection interfaces and loosening of connections caused by random vibrations. The University of Sheffield, Heriot-Watt University and the University of the West of Scotland will develop a sustainable manufacturing process for battery applications, enabling assembly, non-destructive disassembly and reassembly between electrical connections to achieve full recovery of the cells and busbars.
Our EPSRC funding request brings together expertise from across multifarious engineering disciplines: surface engineering and flow dynamics; materials science; joining; AI; and tooling design. We will utilise outputs from previous EPSRC funding projects; e.g., 'NASCENT' to accelerate capability to produce a reversible solution.
| Description | A presentation entitled Development of Non-Destructive Reversible Joining for EV Battery systems was given to the International Institute of Welding's - Young Welding Professionals international conference in February 5-6, 2026. Our University of Sheffield researcher Dr Ragavendran Meenakshisundaram presented an introduction to his work highlighting the potential of using a laser soldering process as a reversible non-destructive joining method applied to EV busbar-cell configuration. The wor |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | A concept study was undertaken to develop and demonstrate a reversible laser soldered joining method for EV battery tab-to-busbar connections. The objective was to show that laser soldering can serve as a viable alternative to permanent welded joints, providing a repairable, recyclable, and non destructive disassembly process that supports more sustainable battery system designs. The initial demonstration employed SAC305 - a solder alloy of composition 96.5 wt.% Sn - 3 wt.% Ag - 0.5 wt.% Cu, used as an intermediate bonding layer between Ni plated copper (C106) battery tabs. By applying an 8 kW laser in conduction (defocused) mode, the solder layer could be repeatedly melted and re solidified to simulate joining and disassembly cycles without degrading the underlying tab materials. Experimental trials produced joints with good mechanical strength and low electrical resistance, while avoiding keyhole and semi keyhole behaviour by maintaining a conduction mode heat transfer. Thermal imaging recorded peak temperatures of approximately 130 °C during conventional soldering and ~360 °C during laser soldering. The joints were successfully assembled and disassembled three times without damage or degradation to the tab materials, demonstrating early proof of concept. Further optimisation of heat management is planned as the research progresses, along with novel tooling systems. These initial outcomes confirm that reversible laser soldered joints for EV battery tabs are technically feasible and offer a promising pathway toward repairable, recyclable, and recoverable battery pack architectures. Future research will extend the method to alternative tab materials such as aluminium (Al10XX) and nickel plated steel, and to multiple cell formats including pouch and cylindrical cells. Additional work packages will explore solder composition modifications for different tab materials, battery tab surface conditioning to refine and control of solder flow, all aimed at improving joint quality and reversibility. This work was presented to approximately 20 attendees at the International Institute of Welding's Young Welding Professionals online international conference, generating engagement and discussion within the welding and battery technology communities. |
| Year(s) Of Engagement Activity | 2026 |
| URL | https://www.ewf.be/events/3rd_young_professionals.aspx |