Paper batteries: Are they for real?
When I first heard about paper batteries, I was skeptical. I have worked with companies that had batteries on mylar and similar materials, but paper?
I was intrigued, so I agreed to speak to Shreefal Mehta, CEO and Dave Rich, Sr. Director at The Paper Battery Company.
The company started in 2008 and are based in upstate NY (RPI grads). Their vision was roll to roll print production of scalable, flexible, structural sheets of energy storage material. The technique would be producing both battery and supercapacitor (energy and power) material on the same high volume print production line.
They are now developing ultrathin supercapacitor technology that they claim will enhance battery performance in mobile devices and other products that rely on traditional rechargeable lithium batteries. The technology is unique, relatively non-intrusive (just .3mm thick), works with existing battery solutions, and is environmentally friendly. With this scalable technology, energy storage and dispensing can be significantly improved, using a cost- and space-efficient sheet-like product that can easily be designed into a variety of electronic products.
They saw the trend in embedded devices getting smaller and thinner and running on batteries, so they went off and developed a thin, inexpensive design for a battery. I wondered how good this technology was.
PBC has also announced a partnership with leading battery pack maker TWS – one of the top five battery suppliers in the world.So I delved a little deeper, asked questions and did some research.
A “doubting Thomas”
I found that the New University in Lisbon, Portugal had done a great deal of research and development of paper thin-film batteries constructed on cellulose paper used simultaneously as an electrolyte, separating electrodes, and a physical support of a rechargeable battery1. As a matter of fact, a 3 V prototype was able to control the on/Off state of a paper transistor.
Then Purdue University, in 2013, created Lithium-ion batteries using flexible paper-based current collectors. The current collectors were fabricated from wood microfibers coated with carbon nanotubes (CNT) through an electrostatic layer-by-layer nanoassembly process2.So, OK---it can be done. Now I was interested in The Paper Battery Company’s design.
The Paper Battery Company process
The company’s PowerPatch™ product line consists of ultrathin, patternable ultracapacitor devices with interconnects and packaging designed to make compact energy modules with operating voltages ranging from 2V – 7.8V depending on the desired life time.
This first generation product implements a limited subset of the PowerWrapper™ technology platform and highlights the packaging innovation developed by the company for this next generation of ultrathin, patternable, ultracapacitors.
As a bonus, this design is an environmentally friendly product: Ultracapacitor technology uses electrodes composed of high surface area activated carbon, carbon nanotubes or graphene. Paper or other porous polymer separators hold the electrolyte and separate the electrodes. Current collectors, usually aluminum foil, attach to the electrodes and carry the charges in and out. The PowerPatch™ products do not have the often-toxic heavy metals typically found in batteries and are RoHS compliant.