Sweet storage solution: novel battery uses upcycled food waste

A novel battery component that uses food-based acids found in sherbet and winemaking could make lithium-ion batteries more efficient, affordable and sustainable, according to research from the University of New South Wales (UNSW).

The prototype, developed and patented by UNSW chemists, is designed to reduce environmental impacts across its materials and processing inputs while increasing energy storage capability.

The single-layer pouch cell currently being optimised is similar to what is used in a mobile phone, only smaller, said lead researcher Professor Neeraj Sharma from UNSW Science.

“We’ve developed an electrode that can significantly increase the energy storage capability of lithium-ion batteries by replacing graphite with compounds derived from food acids, such as tartaric acid [that occurs naturally in many fruits] and malic acid [found in some fruits and wine extracts].”

Sharma said food acids are readily available and typically less aggressive, as well as containing the necessary functional groups or chemical characteristics.

“[Our battery component] could potentially use food acids from food waste streams. Its processing uses water rather than toxic solvents, so we’re improving the status quo across multiple areas.

“By using waste produced at scale for battery components, the industry can diversify their inputs while addressing both environmental and sustainability concerns,” Sharma said.

Sharma leads the solid state and materials chemistry group, part of the cross-faculty batteries research community of practice at UNSW. They work with government and industry partners across all aspects of battery life.

“Our focus is to really understand the materials [used in batteries] and their mechanism during battery operation, and using this understanding we can design better materials,” Sharma said.

“Our research ranges from synthesising new materials, characterising new and commonly used materials and devices, to recycling and end-of-life degradation challenges.”

The need for batteries has increased in recent years as we continue to transition to renewable energy. However, despite many advances, less than 10% of predicted global renewable energy storage requirements have been met.

“Using food acids to produce water-soluble metal dicarboxylates [electrode materials] presents a competitive alternative to graphite used in the majority of lithium-ion batteries that can, as we’ve demonstrated, optimise battery performance, renewability and cost to better support battery demand.”

The team is currently upscaling the technology, increasing production quantities, and transitioning from small coin cell to larger pouch cell capability. The next step will be running use/re-charge cycles at different temperatures to demonstrate industry viability and allow for further optimisation.

The technology is also applicable to sodium-ion batteries, which present a less expensive, greener alternative to lithium-ion batteries.

Image caption: Professor Neeraj Sharma. Image credit: UNSW Sydney/Richard Freeman