Work

High‐Performance Stretchable Gallium Battery for Wearable Electronics, Through Synthesis of Foam Electrodes

Year: 2025

Type: article

Abstract: The demand for sustainable and stretchable thin‐film printed batteries for bioelectronics, wearables, and e‐textiles is rapidly increasing. Recently, we developed a fully 3D‐printed soft‐matter thin‐film Ga‐Ag2O battery with 3R characteristics: resilient to mechanical strain, repairable after damage, and recyclable. This battery achieved a record‐breaking areal capacity of 26.37 mAh cm−2, increasing to 30.32 mAh cm−2 after 10 cycles under 100% strain. This performance stems from the synergistic effects of gallium's liquid metal properties and the styrene‐isoprene‐styrene polymer in the anode. Gallium's high specific capacity (1153.2 mAh g−1), deformability, and self‐healing abilities, supported by its supercooled liquid phase, significantly enhance the battery's resilience and efficiency. However, the cathode's lower theoretical capacity, due to Ag2O (231.31 mAh g−1), remains a limitation. Traditional Ag2O‐carbon black‐styrene‐isoprene‐styrene cathodes experience rapid capacity decay as only the surface area of the active materials interacts with the electrolyte. To overcome this, we designed a carbon‐filled Ag2O foam electrode using a sacrificial sugar template, increasing the effective surface area. This optimization enhanced ion‐exchange efficiency, specific capacity, and cyclability, achieving a specific capacity of 221.16 mAh g−1. Consequently, the Ga‐Ag2O stretchable battery attained a record areal capacity of 40.91 mAh cm−2—double that of nonfoam electrodes—and exhibited fivefold improved charge–discharge cycles. Using ultrastretchable Ag‐EGaIn‐styrene‐isoprene‐styrene and carbon black‐styrene‐isoprene‐styrene current collectors, the battery's specific capacity increased by 33% under 50% strain. Integrated into a soft‐matter smart wristband for temperature monitoring, the battery demonstrated its promise for wearable electronics.

Source: Energy & environment materials

DOI: 10.1002/eem2.12889

Authors: Elahe Parvini, Abdollah Hajalilou, Manuel Reis Carneiro, Pedro Alhais Lopes, Mahmoud Tavakoli

Institution: University of Coimbra

Language: English

Topic: Advanced battery technologies research

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $3,000