Altech Batteries Ltd (ASX:ATC, OTC:ALTHF) describes the progress it is making as “excellent” with two ABS60 60 kWh CERENERGY® battery prototypes being manufactured in Germany to be utilised for customer performance testing.
The manufacturing of the two batteries began last year after Altech’s joint venture partner, German government-owned Fraunhofer IKTS, had initially developed battery packs with capacities of 5 kWh and 10 kWh units.
With the establishment of the joint venture with Altech, a significant upgrade was undertaken, resulting in the transformation of the battery pack into a substantial 60 kWh unit specifically designed for the grid storage market.
Battery pack redesign
Production of two of these substantial 60 kWh battery packs was initiated to conduct performance tests and qualify them for customer use.
To facilitate the manufacturing of 60 kWh battery prototypes, the pilot line at Fraunhofer IKTS in Hermsdorf, Germany, has undergone a comprehensive redesign with innovative tools and machinery developed and implemented specifically.
The battery pack is composed of 240 CERENERGY® cells, each rated at 2.5 V. These cells are organised in four rows, each comprising 12 cells, and stacked five modules high. The dimensional specifications of the battery packs are 2.6 metres in height, 0.4 metres in length and 1.0 metre in width.
Ensuring adherence to the Ingress Protection (IP) 65 standard, the packs are designed to be dust and weatherproof, reflecting high levels of sealing effectiveness for electrical enclosures.
Production of battery cells at Fraunhofer IKTS Hermsdorf pilot plant facility.
Altech advises that all prototype materials have now been procured from specific suppliers.
Production stages
The crucial stages in cell production involve blending ceramic components, high-pressure pressing, tube formation and ultimately sintering at 1,600 degrees celsius over several days.
Fraunhofer IKTS’ pilot plant has successfully navigated the entire ceramic tube production, with half of the required tubes now manufactured.
The battery cathode electrolyte, comprising sodium chloride and nickel powder granules, was produced using the mixing and pelletising equipment at the Hermsdorf pilot plant.
The process of cell assembly, encompassing vacuum filling, heating and welding, is ongoing, resulting in the completion of approximately half of the cells.
To facilitate the infiltration of cathode material into multiple battery cells simultaneously, a vacuum chamber was developed.
Ongoing testing
Promising pass results were obtained from laser welding tests on the battery cells conducted at Precitec GmbH & Co. KG.
To confirm the precise alignment of all components following the welding closure of each prototype cell, a thorough examination is conducted using an industrial micro-computed tomography (µCT) scanning system.
This ensures the verification of filling height, composition, alignment and the behaviour of cathode material post-cell initialisation. Upon successful completion of the µCT quality assurance, individual cells undergo charge and discharge performance tests, all of which have demonstrated satisfactory results as expected thus far.
As of now, 50% of the necessary cells have been successfully produced, showcasing excellent progress. Reject or defect rates have been low and with expected limits.
CCS developed
Once the cells are finalised, they are integrated into a module frame and welded to the specially crafted Cell Contacting System (CCS).
This system, designed by Hofer AG, a supplier for Altech, facilitates pins and bus bar contact with all cells within an electrical isolation frame arrangement.
Hofer AG has successfully completed the development of the CCS, delivering the initial prototype designs for the 60 kWh prototypes.
Altech and Fraunhofer have meticulously validated all electrical specifications and tolerances of the CCS and the electrical isolating material has demonstrated reliable performance.
Delivery of the battery casing and heat loss testing at Fraunhofer IKTS Dresden.
Casings produced
König Metall GmbH has produced and delivered two casings for the 60 kWh battery houses. Fraunhofer IKTS, situated in Dresden, will furnish the testing racks for charge and discharge cycling to assess the battery performance.
Simultaneously, the battery housings are undergoing heating cycles to evaluate the heat loss parameters of the vacuum-insulated casings.
Specialised software has been developed to facilitate access to the parameters that the CERENERGY® BatteryPack will furnish during testing.
The assembly of cells into the battery housing will be undertaken once all cells are finalised and is expected by the middle of 2024.
Customer access
Once the prototypes are completed, which is expected in mid-2024, Altech will provide access to the prototypes to select potential customers.
This collaboration is aimed at demonstrating the practical applications and benefits of the ABS60 series in various industries, whilst also securing offtake agreements.
Main photo: Some of the completed battery cells awaiting performance testing.