Aluminium joining processes for battery cooling systems
The Innovation Exchange is supporting Balance Batteries, through the InnovateUK KTN Net Zero Catalyst programme to find solutions for its cooling system challenge. Balance Batteries wishes to engage innovators to find an efficient aluminium joining process that can join aluminium sheets, for use in its fuel cell and battery cooling system. The solution provider will be able to access part of a £25,000 grant award to work with Balance Batteries on delivery of a proof-of-concept trial.
Opportunity
Challenge opens
13/12/2022
Challenge closes
13/01/2023
Benefit
Shortlisted applicants will be given an opportunity to pitch their solution to Balance Batteries. The final successful applicant will deliver a proof-of-concept trial with Balance Batteries, to demonstrate the solution. The project team will receive a £25,000 grant award, to be apportioned between Balance Batteries and the successful applicant, as agreed on a bilateral basis.
Background
Balance Batteries
Balance Batteries designs and builds electrical energy storage systems, utilising the latest in cell technology, targeted at the most demanding of applications. Using its unique cooling system technology, Balance Batteries can produce systems with exceptionally high power and energy densities. Balance Batteries can design and manufacture battery systems for a specific application. An example of one of its products is presented in Figure 1.
Balance Batteries cooling product
Using the right cell is important for a high-power battery system and will dictate the peak power available. However, the continuous power capability will be dictated by the efficiency of the cooling system. A poorly designed cooling system will add unnecessary volume and weight. Therefore, to ensure high power is available continuously, an efficient cooling system is essential. Balance Batteries are developing an innovate cooling system for battery systems.
Manufacturing the cooling system
The battery cooling system is manufactured from sheet aluminium, formed of two sealed sheets, a top and a bottom. A joining processed is required to seal these two sheets together in a way that does not deform the structure or compromise the properties of the cooling system.
Braising has been trialled by Balance Batteries, whereby the sheets have been heated to create a seal. Usually, this process works well for stainless steel, but it causes deformities in the aluminium structure of the cooling system because it is very thin, and heat dissipates quickly through the structure. Fast heat dissipation is a design feature for the cooling system.
The aluminium sheet is coated in an alloy, which should allow the aluminium to be joined via heat treatment, without compromising the structure, because the alloy’s melting point is above that of aluminium. When trialled by Balance Batteries, the aluminium structure has sagged. Only one supplier has been able to successfully braise the joints, but it is a high performance, precision service provider and the service is not scalable.
Balance Batteries has begun to explore solvents and adhesives but has not fully exhausted this avenue of exploration.
Friction stir welding is a potential avenue for exploration for a solution provider and is advantageous because it can be delivered at room temperature. There is however no known specific method that is at the right accuracy, cost and speed for Balance Batteries to use.
Figure 1: Image of a Balance Batteries battery design
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