If the 2022 World of Concrete was any indication, the heavy-duty capabilities of cordless tools have reached new heights. At the Las Vegas show, all major manufacturers displayed comprehensive arrays of battery-powered tools capable of cutting, drilling and grinding concrete and chipping hammers for demolition.
The development of compact, powerful cordless tools over the past few years has made a positive impact on jobsites. Setting up for work is much more efficient now that power cords, outlets and generators are largely eliminated. Workers can quickly and easily move from task to task. Power cable hazards and electrical circuitry concerns have been reduced.
But how powerful can these cordless tools get?
At the heart of all these are rechargeable lithium-ion battery packs, typically 20 and 40 volt units, used either singly or in groups.
Lithium is constantly in the news. It has found wide application as a power source for devices as small as watches and as large as EV transport trucks.
The adoption of lithium-ion has accelerated the practicality of cordless tools. Earlier versions of cordless tools used nickel cadmium (NiCad) batteries, explained Sean Fitzgibbons, group product manager for Stanley Black & Decker. Among various concerns, NiCad batteries suffered from environmental and over-charging problems.
However, there are also limits to what lithium-ion battery packs can do, particularly when it comes to the balance between deliverable power and the size and weight of the power units.
“If more power/runtime is desired, one could either add more cells to the battery, or increase the cell size, but either choice leads to a size/weight penalty for the end user,” Fitzgibbons told the Daily Commercial News.
DEWALT’s solution has been development of POWERSTACK ™ 20V MAX compact batteries. The company says these provide 50 per cent more power while being 25 per cent smaller and 15 per cent lighter.
DEWALT intends to, “leverage this technology to service a broadening spectrum of user needs,” Fitzgibbons said.
“We envision the development of new batteries with POWERSTACK™ Battery Technology to correspond with the expansion of cordless tool applications.”
Longer term, however, is the question of lithium-ion’s future.
Rapid demand growth, particularly over the past five years as EV production has ramped up, has resulted in a global shortage of lithium and prices eight times higher today than 12 months ago.
Aside from price increases and supply shortages, the process surrounding lithium’s production is an increasing concern. Although an element on the periodic table, lithium does not occur freely in nature but instead is found bonded to igneous rocks. Consequently, the heavy use of groundwater, soil and water pollution, and the carbon emissions associated with mining, are viewed as environmentally harmful as any end-use fossil fuel reduction benefits derived from lithium batteries.
Cobalt, typically used in lithium-ion batteries, is also questioned due to human rights abuses and the mining techniques in the Democratic Republic of the Congo.
In response to these numerous issues, experiments are being conducted all over the world in an effort to find alternatives for lithium-ion.
While researchers at the University of Texas at Houston believe a rechargeable cobalt-free battery is one day possible, they have in the meantime developed sodium-sulphur batteries that resolve many of the concerns surrounding lithium-ion. Both sodium and sulphur are cheaper and more widely available than both lithium and cobalt. These developments also address the issue of dendrites in the battery structure that can cause rapid battery degradation, short-circuiting, fires and explosions.
NAWA Technologies based in France has designed and patented an Ultra-Fast Carbon Electrode that they say boosts battery power 10 times and battery life cycle five times, while increasing energy storage three times.
At the University of California-San Diego, engineers have conducted tests of an all-solid-state silicon battery that may have wide applications. And at nearby UofC-Irvine, nanowire batteries have been found to be capable of so many recharging cycles that they might last forever.
Lithium aside, this points to a promising long-term future for rechargeable cordless tools.
John Bleasby is a Coldwater, Ont.-based freelance writer. Send comments and Inside Innovation column ideas to firstname.lastname@example.org.