Next Up For EV Batteries: A Paper-Like “Wonder Material”

Move over graphene, we’re looking at the next nanomaterial of the new millennium. That would be the super-miniscule wood fibers known as nanocellulose, and the South African company Sappi is already moving forward with plans for a pilot-scale plant to demonstrate a new method for prying the little guys loose from wood.

If the project is successful, you’re going to see nanocellulose working its way into all kinds of clean tech applications — maybe not quite as many as graphene, but we’re thinking EV batteries for starters.

Nanocellulose fibers (screenshot, courtesy of TAPPI).

So…What Is This Nanocellulose You Speak Of?

We must have been asleep at the wheel because this stuff is new to our radar, but the US Department of Agriculture is all over nanocellulose like white on rice. Here’s why:

Nanocellulose is simply wood fiber broken down to the nanoscale…Materials at this minute scale have unique properties; nanocellulose-based materials can be stronger than Kevlar fiber and provide high strength properties with low weight. These attributes have attracted the interest of the Department of Defense for use in lightweight armor and ballistic glass.

USDA also cites interest from the private sector for automotive and electronics applications among many other fields.

In fact, USDA is so excited about nanocellulose that is kicked in for a nifty little video produced by TAPPI (the Technological Association of the American Pulp and Paper Industry — start at the 2:15 mark to skip the fluff and cut to the mustard):

EV Batteries Made From Wood

As a substitute for glass fiber, nanocellulose has obvious applications for lightweight car body parts and other structural elements, but that’s just the beginning. We just came across a new paper published at the National Institutes of Health suggesting that nanocellulose could be used to create “paper-like” electrodes in energy storage devices.

So there’s your paper EV battery. Maybe not for another ten years give or take a few (just guessing there), but in an age when the auto industry is experimenting with all sorts of renewable materials from dandelion sap to coconut husks, why not wood?

We have no idea why this paper showed up at NIH (the lead authors are from the Department of Chemistry-The Ångström Laboratory, at Uppsala University in Sweden), but you can find it under the title, “Freestanding nanocellulose-composite fibre reinforced 3D polypyrrole electrodes for energy storage applications.”

Also, group hug, you taxpayers. In 2012, USDA’s Forest Service Forest Products Lab revved up a production facility for nanocellulose, making the first facility of its kind in the nation.

Sappi Solves Nanocellulose Problem

Before you can even get to your paper EV batteries, you have to figure out a way to manufacture nanocellulose at commercial scale. That’s a problem because conventional methods for mashing wood fiber into nanocellulose involve loads of chemicals and tons of energy.

That’s where Sappi comes in. Following upon a three year research partnership with Edinburgh Napier University, the company is building a pilot scale facility to produce what it calls Cellulose NanoFibrils.

Napier Professor Rob English, who headed up the research team, enthuses thusly:

What is significant about our process is the use of unique chemistry which has allowed us to very easily break down the wood pulp fibers into nanocellulose.

There is no expensive chemistry required and, most significantly, the chemicals used can be easily recycled and reused without generating large quantities of waste water.

It produces a dry powder that can be readily redispersed in water and leaves the nanocellulose unmodified – effectively making its surface a chemical “blank canvas” and so more easily combined with other materials.

If you’re still thinking dream on, Klingon about that paper EV battery thing, Professor English also notes that “..there are also applications for it in containing films in lithium batteries and touch screen displays.”

Weirdly, English also foresees applications in regenerative medicine, which makes us think that in the sparkly green future you and your car might be sharing more than a few of the same body parts. Come to think of it, that accounts for why the National Institutes of Health is so interested, but we digress.

Sappi is looking at a global market for nanocellulose of 35 million tonnes (that’s tonnes, not tons) per year in relatively short order, say by the mid-2020s.

Don’t Look Back, Sappi…

Sappi better keep moving along if it wants to stay ahead of the game. The US pulp and paper industry is already looking beyond nanocellulose. They’re zeroing in on something even smaller and potentially stronger (as in, strong as metal strong): cellulose nanocrystals.

We might have been in dreamland while the nanocellulose thing was happening, but we did take note last year when Purdue University positioned itself as Cellulose Nanocrystal Central with a new key for unlocking the mechanics behind their property. This is how small they are:

The nanocrystals are about 3 nanometers wide by 500 nanometers long – or about 1/1,000th the width of a grain of sand – making them too small to study with light microscopes and difficult to measure with laboratory instruments.

As our new BFF George Takei would say, oh my!

Structural detail of cellulose nanocrystal by Pablo Zavattieri, courtesy of Purdue University.

Not for nothing but Purdue is eyeballing energy storage as a major application for cellulose nanocrystals, envisioning “flexible batteries made from electrically conductive paper.”

If that comes around, go ahead and give yourselves another group hug, taxpayers. The cellulose nanocrystal research under way at Purdue is partly funded by the USDA.

We did say they are obsessed, didn’t we?

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