Strategic Elements (ASX: SOR) announced its investee Australian Advanced Materials has breached the 4-volt self-charging battery barrier as part of ongoing research and development work on a prototype battery pack containing multiple connected battery ink cells.
Currently in development in partnership with the CSIRO and the University of New South Wales, the self-charging battery ink technology generates electricity from humidity in the air or skin surface.
The pooled development fund declared that to date, the technology has demonstrated “strong early-stage potential” after early prototypes were scaled up to 1-litre ink batch size and now increasing from 0.8V in a single cell to a maximum voltage of 4.4V from the first prototype battery pack developed.
The self-charging battery technology has strong potential competitive advantages over traditional batteries and power sources that suffer from flexibility, dimension, weight and safety issues whilst needing a constant power supply or to be charged.
The company is currently designing a hybrid electric generator with an initial market focus on wearables and IoT-related devices such as skin patch sensors. R&D work is also evaluating a flexible textile material prototype and harvesting energy from the environment in a carbon-neutral way.
However, the fund conceded that higher performance applications are likely to require the development of a capacitor for energy storage and regulation and will be addressed at a later date.
Strategic Elements said the 4.4 volt achievement was a “significant milestone” in developing the self-charging battery technology.
“Early observations suggest battery ink cells have the potential to be reduced in size whilst still generating a similar level of voltage (0.8V). Significantly, this could potentially enable development of much smaller devices or greater energy generated from a specific area.”
Strategic Elements managing director Charles Murphy said that given the encouraging achievement of early milestones, the fund would be adding PhD material science expertise and developing a panel of industry specialists.
“The technology sits across two of the strongest 2021 investment sectors in batteries and environmental technologies and is a very good fit for our high-risk, high reward pooled development fund structure,” said Mr Murphy.
As a result of ongoing R&D work, five 1cm-square battery ink cells weighing less than 3 milligrams and thinner than a human hair were fabricated onto glass.
The cells were then “serially connected” and placed in a testing chamber with 75% humidity, given that “human skin is known to generate elevated levels of humidity to 90%.”
According to Strategic Elements, the prototype battery pack sustained an open circuit voltage output exceeding 4 volts over a 5-hour testing period and achieving a maximum of 4.4 volts.
Moreover – and as an early insight into the potentially extensive applications of the technology – voltage output was sustained above 4V despite the humidity level being reduced to 55%, without suffering from degradation.
Additionally, the most recent prototype demonstrated a marginal improvement in self-charge capability through harvesting energy from humidity and manipulating moisture in a testing chamber.
Reducing the humidity to less than 1% meant voltage output was reduced to 0.17V, as expected. However, as humidity was restored, the battery pack returned to producing its peak voltage.
As a result of achieving several development milestones in recent months and now breaching the 4-volt barrier as part of its development program, Strategic Elements said it filed a patent application on Wednesday this week and confirmed further work is planned to test its battery ink cells under varying humidity levels.
“Further development on reducing battery ink cell size whilst retaining the same voltage output, and, developing battery ink cells capable of being fabricated onto a flexible textile material has commenced,” the company said with the next development milestone being to develop battery ink cells “up to four times smaller than the existing cells”.
“My group at UNSW have developed deep experience in printed electronic inks, energy harvesting and storage over the past nine years. Although still under development the battery ink is developing promisingly as an electrical generator battery technology. Our strong collaboration with the Strategic Elements team is enabling us to move forward expeditiously,” UNSW Professor Dewei Chu said.