Developing fast-charging lithium ion battery for trams
We’ve designed a high power battery specifically for the rigours of light rail.
While supercapacitors may be considered optimal for this application, they are not the best solution for trams. Supercapacitors have the power to move the tram from a stop and recover a substantial amount of energy during braking at the next one, but they can only do this for short periods of time. Also, to move a tram the required distances will require thousands of supercapacitors, potentially leading to the pack weighing more than the tram!
Our battery blends all that is good about the supercapacitor (high power and long cycle life) and all that is good about the battery (high energy). By using lithium iron phosphate (LFP) cathodes (you’ll know this material as the stuff that does good things in battery operated power drills), we can design a high power, high energy device with long cycle life.
With our device, a tram battery pack can be charged in 90 seconds – the time it takes passengers to get off the tram and new passengers to board. The pack lasts at least three stops before needing to be charged again, and can be charged over 25,000 times, which is equivalent to stopping 75,000 times! That’s a whole lot of sustainable tram journeys without the poles and wires! And at the end of life of the battery, we can recycle the cells and ensure a truly sustainable technology solution.
We hope to see it applied to Light Rail systems not only in Melbourne, but all around the world!