Eco friendly low-cost energy storage system from pine biomass

Madrid, Spain (SPX) Mar 10, 2025
The challenge of storing renewable energy efficiently remains a crucial factor in advancing sustainable power solutions. Since renewable energy sources such as wind and solar are inherently variable, effective storage systems are necessary to balance supply with demand. "In the field of renewable energies, we cannot control the wind, heat, light, etc., that nature offers us. And the energy demand sometimes does not coincide with the energy supply; so resources need to be developed to store that energy produced by renewable systems," said Eider Goikolea, a researcher from the Solid State and Materials Research Group.

Researchers from the group, including Eider Goikolea and Idoia Ruiz de Larramendi, both lecturers at UPV/EHU, are working on innovative materials for next-generation electrochemical energy storage. "We develop new materials that can be used to store energy. In this case, to create electrodes, we prepared carbon from wood particles of insignis pines, which are widely available and often discarded as sawdust in carpentry workshops. This sawdust, despite being waste, has a high carbon content," explained Idoia Ruiz de Larramendi.

Hybrid energy storage system

Energy storage technologies such as batteries and supercapacitors each have distinct advantages. While supercapacitors deliver high power rapidly, they store less energy than batteries. "Supercapacitors are not suitable for providing energy over a long period; unlike batteries, they are used when a large amount of energy is needed in a short burst," Goikolea noted.

In this study, the research team developed a hybrid lithium-ion storage device that integrates the benefits of both batteries and supercapacitors. "This system allows for high-power energy storage similar to batteries while maintaining the capability of supercapacitors to endure many charge-discharge cycles," she added. The device combines a battery-type electrode and a supercapacitor-type electrode to optimize performance.

The electrodes were made using different forms of carbon. "Carbon is a broad term encompassing various structures, and not all biomass-derived carbon is suitable for this application. However, we demonstrated that insignis pine biomass delivers excellent results," said Ruiz de Larramendi. One electrode was composed of hard carbon, while the other utilized activated carbon. Additionally, a key aspect of the research was ensuring cost-effectiveness and sustainability in electrode production. "The synthesis process was energy-efficient, maintaining temperatures below 700 C, and employed economical additives," she noted.

The study demonstrates that locally available biomass can be a viable, sustainable alternative to conventional lithium-ion capacitor materials. "Materials derived from biomass hold great promise for developing eco-friendly, cost-effective high-power energy storage solutions. It is essential to continue research in this direction," emphasized the UPV/EHU researchers.

Research Report:A forestry waste-derived lithium-ion capacitor: Sustainable, high-power energy storage