Lead‒acid is the world’s most mature commercial battery and lithium-ion has emerged as an alternative in certain applications, including energy storage. Both battery chemistries present clear advantages. Recent literature has demonstrated that separate lead‒acid and lithium-ion batteries can be connected in parallel to a common busbar and cycle together without the need for electronic control, e.g., DC-DC converters.
This presentation discusses the unique configuration that combines favourable characteristics from both battery chemistries. Furthermore, this can produce the lowest total cost of ownership when operating over a broad time window that is covering a range of applications from ancillary services to daily cycling. A key aspect of this dual chemistry system is that the lithium-ion battery discharges first, followed by the lead‒acid battery. This is achieved by using a slightly higher nominal voltage for the lithium-ion battery (~5-12%). Both chemistries are charged together. Here, the profile is analogous to a typical lead–acid remote area power system.
This work combines gel lead‒acid batteries with lithium iron phosphate (LFP) and lithium-ion batteries. There is an inflection point when the lithium-ion battery approaches full-discharge. This coincides with a sharp voltage knee, which is characteristic of LFP batteries. In another workstream, a lead‒acid system approaching the end of its service life was retrofitted, transforming it into a dual chemistry power system. After operating for a few more years, this demonstrates that a dual chemistry duty cycle can extend the service life of lead‒acid batteries.
Presenters
Michael Glenn obtained his PhD researching fuel cells at The University of Newcastle in 2017 followed by a postdoctoral fellowship in this field. He then joined the battery industry, working on battery management strategies for the UltraBattery®. Currently, he is the Principal Technical Development Officer at Battery Energy. This encompasses projects in battery management systems, advanced gel battery enhancement and lithium-ion battery integration. He has served various roles in developing energy storage systems across three battery chemistries, i.e., lead–acid, lithium-ion, and zinc bromine.
Vaishnavi received her masters degree in chemical engineering from UNSW in 2019. Following this, she became a product development engineer at Battery Energy where she has made a significant contribution. Her responsibilities include: • Managing both product development and R&D projects. • Extensive research and analysis of VRLA and LFP batteries. • Creating and designing 3D models and technical/ mechanical drawings using SOLIDWORKS. • Preparation, interpretation and review of calculations, specifications, plans, investigations, surveys. • Standardising test procedures, equipment and protocols. • Preparing test plans and executing experiments by conducting literature research. • Applying diagnostics to investigate failure/destructive mode analysis.
Dr David Brown has over 45 years working with batteries. After obtaining his first degree and PhD he spent 4 years doing postdoctoral research in Germany and France. He then moved to Lucas Research Centre, heading a large EV team, involving Ni/Zn/Cd technology. This was followed by Technical Manager for Besco batteries in Australia, then setting up Battery Energy in 1987 to manufacture industrial lead acid batteries. He has remained with the company, currently as a consultant, responsible for all technical developments, including advanced gel technology with CSIRO and setting up of production in China under licence.
