In what could turn out to be one of the major battery technology events of the last 100 years, Stanford University has announced the creation of the first self-healing battery. This sounds very grand and very eye-catching but what exactly is it and how could it turned out to be one of the most important developments in battery technology?
The development is connected with lithium ion batteries which are the technology of choice for the electric vehicle industry at this moment in time. However one of the main problems with lithium ion batteries is the fact that the recharging cycle continuously erodes the battery life as cracks emerge on the various electrodes which hold the power and transfer this to, at least in this instance, an electric vehicle.
A new self-healing skin
Stanford University has managed to create a polymer which is used to coat electrodes in a lithium ion battery. As the battery is recharged, used, recharged, used, etc., the electrodes expand and contract which eventually causes cracks to merge. This new polymer is very flexible and when the electrodes expand and contract it separates and stretches the long molecule chains to the limit. The research team found a way to weaken these long molecule chains yet further and discovered that once they were separated they would automatically find each other again to form a new bond.
Quote from ElectricForum.com : "The name HEVO is one you could hear a lot more over the next few years after the company released an intelligent manhole cover which is capable of recharging an electric vehicle, wirelessly, while parked above it."
If we can explain this in simple terms, it is like the human skin, which stretches and is able to self-heal when there are cuts and abrasions. So no matter how many times the electrodes expand and contract, no matter how many times they are recharged, there is the potential, in theory, to repair them on an ongoing basis.
How far developed is the technology?
At this moment in time, Stanford University has been able to monitor this new polymer over 100 charging cycles of a polymer coated lithium ion battery. The results show that there was little in the way of damage to the electrodes and indeed no significant loss of energy storage capacity. This is most certainly a very interesting steppingstone to a much more developed technology because while 100 charging cycles is a start, we need to be talking in the thousands before it is commercially viable.
Using the same polymer and the same system, researchers at Stanford University are now looking to repeat the recharge cycle 3000 times for a selection of electric vehicle batteries. They will then monitor any loss in storage capacity and then look to rectify any issues before moving on to even greater recharge cycle numbers.
At the moment, this new polymer seems to be potentially the breakthrough that the battery technology industry has been crying out for. The ability of a lithium ion battery to effectively self-heal over a prolonged period of time could take the EV sector to a new level. This work has been funded by the US government and shows that while the authorities have come under pressure for ill-advised investments in the past, when done correctly it can potentially be a game changer.