Your Next Battery Could Be Printed on Paper

Supply chain turmoil seems to be everywhere, spanning out from semiconductors and into a range of commodities. With commodities and natural resource prices fluctuating so much in the face of geopolitical events, and with growing demand for electric vehicles, the world could see a lithium shortage by 2025 (according to an assessment by the International Energy Agency). In the face of growing lithium demand, researchers in academia and industry have looked into alternative battery materials to overcome these challenges.

One of the most interesting developments was produced by researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa). The research findings were published in a recent issue of Nature. They announced an innovative water-activated battery material that is printable on a sheet of paper. In theory, this electrochemically active material could be printed on any substrate material, such as a flexible insulator like plastic.

While no one is suggesting the use of paper batteries for electric vehicles, the material can output at up to 1.2 V in a single cell (comparable to Ni-MH battery chemistries). Therefore, stacks of this type of material could be used as a small disposable battery for handheld electronics or other small devices. This is not the magic bullet for lithium shortages, but these alternative materials could allow the diversion of lithium into much more critical areas like EVs.

An Ink-Based Battery Material

The material developed by the researchers at Empa is actually a carbon-based layered material that involves graphite, carbon black, zinc as the anode, and salt. The carbon-salt-based chemistry can be activated with the application of water, as described below. The layered structure of this battery material is shown in the graphic below.

The top and bottom layers of graphite + carbon black act as the active layers that participate in the battery’s electrochemical reaction. When coated with a salt and exposed to water, the resulting electrochemical reaction can cause current to flow through a connected circuit.

This particular discovery is not a viable system, it is only a demonstration of a new chemistry that does produce enough power to run small electronics. The power output being compatible with Ni-MH and alkaline batteries shows that the material is viable from an electrochemical standpoint. The commercial aspect is another matter, as I outline below.

So is this a replacement for the standard battery chemistries we are all familiar with? Probably not, but carbon materials are being used in Li-based chemistries as an anode material, providing several benefits for electrified systems.

Alternative Materials Attractive, But Long Runway

Although alternative battery materials intended to totally substitute existing chemistries (including lithium) are an ongoing research topic, this avenue has a long runway and the path to commercialization is fraught with risk. Therefore, the battery materials industry has focused on battery design improvements, including the use of similar materials that improve battery operation without changing the chemistry in batteries.

Why should we care about battery chemistry changes? From the perspective of sustainability and ensuring electrification the demand can be met, finding an alternative chemistry that will be comparable to lithium is an attractive avenue. The problem comes from commercialization: Li-based and other metal-based chemistries are well-understood and have already been qualified from a safety perspective. This makes building on top of the fundamental Li-based chemistries an attractive option from a risk and liability perspective. If new chemistry is developed and there is a path to commercialization, the new chemistry will need to demonstrate some level of regulatory compliance as well as proof of reliability to customers.

For these reasons, the recent focus among battery industry materials developers has been on using carbon materials for incremental improvements within existing battery designs. Battery designers can leverage existing battery manufacturing, testing, and quality control knowledge in these new battery designs while still receiving the benefits of carbon-based chemistry.

Some of the major benefits of carbon-based materials used in existing battery chemistries include:

One of the major carbon-based materials being developed to improve Li-ion batteries is functionalized graphite, which can be readily manufactured and used to build anodes for Li-ion battery systems. Another carbon-based material is carbon nanotubes, which benefit from their high ballistic charge transport along the axial direction. When incorporated in battery systems, these materials offer greater charge/discharge rates and capacities in an already reliable battery chemistry.

As more of these battery systems come to market and designers can incorporate these into their systems, make sure you use the advanced search and filtration features in Octopart to find all the advanced components you need for electrified systems. When you use Octopart’s electronics search engine, you’ll have access to up-to-date distributor pricing data, parts inventory, and parts specifications, and it’s all freely accessible in a user-friendly interface. Take a look at our integrated circuits page to find the components you need.

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