Power Tool Battery Technology: Looking Beyond Lithium-Ion
Reliable power tools are crucial to maintaining the reputations of electrical, cable and telecom companies. Engineers and field technicians, however, are bound by the technical limitations of Lithium-ion battery packs, which present a series of drawbacks.
By Stephen Voller
Reliable power tools are crucial to maintaining the reputations of electrical, cable and telecom companies. Engineers and field technicians, however, are bound by the technical limitations of Lithium-ion battery packs, which present a series of drawbacks. A newly developed innovation, Carbon-Ion cell technology, may offer key advantages over Lithium-ion. How does it represent a potential advance for the industry?
Lithium-Ion: Some Drawbacks
When engineers or field technicians arrive at a worksite to install or maintain equipment, they normally carry their power tools with them. Although the tools themselves are largely reliable, their Lithium-ion battery packs represent a weak link. For example, if there has been insufficient time to recharge them since the last job, the workers will appear unprofessional and unprepared. Just as mobile phone users constantly worry about the state of charge of their phones, field technicians are forced to worry about the state of charge of their cordless power tools.
On arrival at a worksite, the first thing a utility worker may look for is a power socket to plug in a spare battery. The nearest socket may be located at a distance from the worksite, so time and effort is wasted swapping out batteries. In addition, Lithium-ion battery packs have a relatively short life cycle, with some 1,000 charge and discharge cycles before they begin to deteriorate. Consequently, the packs typically have to be replaced every other year at significant expense to the company. Additionally, many tool manufacturers introduce new models on a regular basis; the new tools may no longer be compatible with the existing battery packs and chargers, and battery packs for older tools may no longer be available. This means not just buying new battery packs but also often replacing perfectly good power tools.
Furthermore, even if charged, it is possible the tools may not function as desired because the Lithium-ion battery packs cannot deliver enough torque. This can manifest itself, for example, when a drill motor operates but does not generate sufficient torque to turn a screw or drill a hole.
Finally, Lithium-ion battery packs are known to pose a potential safety risk. Tests have been conducted on commercially available battery packs where the pack was penetrated by a nail; the pack immediately burst into flames, releasing toxic smoke. Clearly, with millions of cordless power tool batteries in use every day, there are serious safety concerns.
Carbon-Ion Cell Technology
In contrast to Lithium-ion, Carbon-Ion powered cordless tools can be fully charged in minutes rather than hours, eliminating the need for technicians to waste time waiting at a worksite. Carbon-Ion powered tools also provide a contact torque so the tools can be relied on to turn the motor to complete the job. In addition, Carbon-Ion battery packs last much longer than their Lithium-ion counterparts, specifically up to 100,000 charge and discharge cycles. This means that Carbon-Ion power packs will outlast the power tool in most cases, providing a much lower total cost of ownership as well as avoiding the issues associated with the need to replace tools on a regular basis.
Carbon-Ion cells combine the fast-charging characteristics of a supercapacitor and - within a few years - are anticipated to match the energy density of Lithium-ion batteries, while also being safe and recyclable. Unlike Lithium-ion, which is a battery and works by an electrochemical reaction that is the source of the risks that have been publicized by the media, Carbon-Ion cells pose no similar risk. This is because they incorporate a new, less-volatile type of electrolyte - called an “ionic electrolyte” - that does not contain any of the flammable chemicals in the “organic electrolytes” used in Lithium-ion batteries.
Although Carbon-Ion cells are not intended to be retrofitted into existing tools that currently employ Lithium-ion batteries, work has already begun to design and build a new generation of cordless tools that incorporate Carbon-Ion cells. At CES 2017, an 18-volt power drill was showcased where the recharge time was reduced from 30 minutes to less than two minutes - and the product will be available for purchase by the end of 2017 or early 2018.
Lithium-ion power tools will most likely always be commercially available in one form or another. However, the advantages of Carbon-Ion cells will increasingly be recognized by utility companies and will likely be a progressively more popular option as time goes by - and occupy an increasing portion of the market because of the perks they offer.
For these reasons, Carbon-Ion represents a potential way forward that could benefit a range of utility companies and their customers alike.
About the author: Stephen Voller is CEO and founder of ZapGo Ltd, a technology company based at the Harwell Research Campus, Oxford, England, with a Charlotte, NC, office. Using nanocarbon materials as well as proprietary electrolytes, the company produces an ultrafast, safe, recyclable charging power module that charges in less than five minutes.