Shape-shifting fluid battery demonstrated by scientists

Researchers at Linköping University have made a groundbreaking advancement in battery technology by creating a soft and flexible battery based on fluid electrodes. This innovative design allows the battery to be molded into any shape, opening up new possibilities for its integration into future technologies.

The fluid battery technology is particularly well-suited for use in miniature medical devices like insulin pumps, pacemakers, hearing aids, and health monitoring sensors. It also holds promise for applications in soft robotics, e-textiles, and connected nerve implants, offering a versatile power source for a wide range of devices.

Aiman Rahmanudin, an assistant professor at Linköping University, describes the texture of the battery material as similar to toothpaste. This unique characteristic enables the battery to be shaped using a 3D printer, providing a new avenue for technological development and customization.

Traditionally, batteries have been solid and bulky components in electronics, imposing design limitations. However, with the introduction of a soft and conformable battery, these constraints are eliminated. The flexibility and adaptability of the new battery design allow for seamless integration into electronics, offering a fresh approach to device construction.

Collaborating with colleagues at the Laboratory of Organic Electronics (LOE), Aiman and the team have successfully transformed solid electrodes into a liquid state, resulting in a soft and malleable battery. This innovative approach addresses the challenge of maintaining high capacity in a battery without sacrificing flexibility.

Previous attempts at creating soft and stretchable batteries have focused on mechanical functions like rubbery composite materials or sliding connections. However, these solutions did not address the fundamental issue of maintaining capacity while ensuring flexibility. The breakthrough achieved by the researchers at Linköping University demonstrates that capacity can be independent of rigidity in a battery.

Unlike earlier experiments with fluid electrodes using materials like gallium, which risked solidifying during charging and discharging, the new battery design utilizes conductive plastics and lignin. Lignin, a byproduct of paper production, contributes to the sustainability of the battery material, making it an environmentally friendly alternative.

The soft battery developed by the researchers can be recharged and discharged over 500 times while retaining its performance. It also exhibits remarkable stretchability, being able to double its original length and still function effectively. This durability and flexibility make it a promising candidate for various applications.

Looking ahead, the researchers aim to enhance the electrical voltage of the battery to improve its performance. Aiman Rahmanudin highlights the current voltage of 0.9 V and discusses exploring the use of other chemical compounds like zinc or manganese to increase the voltage output. These efforts signify ongoing research to optimize the battery for future applications.

With a focus on sustainability and innovation, the development of this soft and flexible battery represents a significant step forward in battery technology. By repurposing abundant raw materials like conjugated polymers and lignin, the researchers have created a circular model for battery production, contributing to a more environmentally conscious approach to energy storage.

Image: Researchers at Linköping University have developed a battery that can take any shape. Credit Thor Balkhed.