Lithium-ion batteries

“The smell of sulphuric acid disappears”

The KION Group's new focus on lithium-ion batteries: efficient, powerful and particularly suitable as an energy source for electric motors and electronic devices.



The idea is certainly appealing: a battery that doesn’t need replacing, delivers a better performance and can be recharged quickly. Sounds familiar? That’s because we already use lithium-ion batteries in a number of everyday electrical devices instead of the less efficient lead-acid batteries. They can be found in smartphones, cordless screwdrivers and digital cameras. “Everyone has heard of them,” says Harald Will, Chief Technology Officer at Linde Material Handling. “But when it comes to warehouse technology, many customers are still put off by the higher price. And that also means that they probably aren’t aware of the benefits.”

On electric commercial vehicles, such as forklift trucks, lithium-ion batteries are still waiting to make a breakthrough. Such vehicles are usually powered by lead-acid batteries, which require a complicated infrastructure: space to change them, areas to store them, equipment with which to handle them – and many individual processes that cost time and money. Bearing all that in mind, the lithium-ion battery already compares quite favourably, despite the higher price.

Lithium-ion technology is already worthwhile

In addition, lithium-ion batteries have significantly greater charge efficiency and operate more efficiently. They require around a third less charge than lead-acid batteries for the same performance because they consume less. “Our research shows that it already pays to use lithium-ion batteries for around a third of applications,” says Will. This is particularly the case for heavy-duty operations where two or even three lead-acid batteries would be used over the same period of time. This could include shift operations in logistics companies or applications in particularly demanding conditions such as in foundries or metalworking plants.

Explained in simplified terms, a lithium-ion battery works as follows: lithium ions move to and fro between the anode and cathode, which are made of lithium metal oxide and graphite respectively – and generate a flow of current. The materials themselves are currently the subject of research: “It may well be that in five years’ time we have very different anodes and cathodes, which are lighter or last longer”, says Will. There is considerable research into lithium-ion batteries at the moment and many possibilities are opening up. That is precisely what makes them such an attractive and promising technology of the future.

Technology of the future: everyone is involved in research

“If you talk to car manufacturers, they are already convinced that we will see major breakthroughs in battery technology,” says Hagen Adam, Director of Product Development at STILL. “There is no reason why electromobility should be more expensive than other drive systems in the long term.” The cost is not driven up by special materials or a particularly complicated manufacturing process. The current price simply reflects the starting point on the price curve for a new technology. And this curve will dip as soon as more are produced – Adam is confident of that.

Demand is already increasing. There is certainly a great deal of curiosity surrounding lithium-ion batteries. “There are more interested customers than I would have expected,” says Adam. So it’s hardly surprising that many organisations are currently getting involved in research into battery technology: chemical companies are conducting studies into the best materials and battery manufacturers are bringing their own products onto the market. The crucial interface, however, is where the battery is connected to the vehicle. “Assembling the cells, managing regenerative power – that is our job,” says Will. Lithium-ion batteries have to be connected correctly to ensure that they are used efficiently and, above all, that they can function safely. The KION Group is one of the leaders in the field in this aspect of development. “We believe that our technology is currently more advanced than that of our competitors,” says Will.

What will the truck of the future look like?

There could be a sudden change in demand in the very near future. That would mean that companies that are already planning series production are at an advantage. “For customers wishing to use lithium-ion technology, the best approach would be to completely switch over their operations from the outset,” says Adam. “What is the point of maintaining two different infrastructures?” A major project for the KION Group, therefore, is developing a lithium-ion variant for all trucks manufactured by the premium brand companies Linde and STILL. It is estimated that 75 per cent of all KION electric trucks will be powered in this way by 2018. For the time being, different drive systems will be mounted on the same platform to allow for maximum flexibility. “As soon as we achieve a higher number of units, it will get really interesting,” says Adam. It would then be conceivable to have lithium-ion batteries in other sizes and designs than those of conventional lead-acid batteries. And engineers would be able to plan completely differently, says Adam. “Think of what we have always wanted to achieve with a truck but couldn’t, because the battery got in the way.”

There is one question still to answer: what is the best way of charging the batteries? Here too there is a whole host of options that allow plenty of room for innovation: the socket on the wall, the onboard charging device – perhaps the most exciting of all – inductive charging: trucks could be charged using a base plate while parked, or even using induction charging strips whilst driving. This is already possible today – but there is still some way to go before it is ready for widespread use. Remaining issues, such as the higher voltage or larger range, are not a problem from a technological viewpoint. The engineers at STILL and Linde are confident that they can overcome these challenges. The warehouse of the future is only a question of time; doing away with battery-changing areas means more free space. And, as Adam predicts, “the smell of sulphuric acid will disappear”.

New technology supports automation

The lithium-ion battery could also be a facilitator for another development, namely the concept of ‘Industry 4.0’ and the automation of warehouses. At first glance, the method of powering trucks, which can operate fully automatically and communicate with each other, may seem irrelevant. “But if a tugger train doesn’t have to stop to charge up and can instead be charged by induction, it can operate automatically around the clock,” says Will. The two big trends for the future appear to go hand in hand.