Bioinspired Self-Assembled Single-Atom Iron-Based Biodegradable Supercapacitors with Intensified Capacitive Kinetics for Implantable Acupoint Electrostimulation

TY - JOUR

T1 - Bioinspired Self-Assembled Single-Atom Iron-Based Biodegradable Supercapacitors with Intensified Capacitive Kinetics for Implantable Acupoint Electrostimulation

AU - Pang, Haotian

AU - Zhu, Chang

AU - Zhang, Yanyan

AU - Guo, Bowen

AU - Lin, Liangru

AU - Xie, Shiwang

AU - Wang, Xinran

AU - Ding, Yixin

AU - Liang, Shiyuan

AU - Wang, Engui

AU - Yin, Peng

AU - Liu, Cong

AU - Li, Zhou

AU - Luo, Dan

N1 - Publisher Copyright: © 2026 Wiley-VCH GmbH.

PY - 2026/6/1

Y1 - 2026/6/1

N2 - Biodegradable supercapacitors represent a promising alternative to conventional power sources for implantable electrical stimulation therapies. However, their development has been impeded by the lack of electrode materials that simultaneously offer high-density redox-active sites, efficient charge transport, and biocompatibility under physiological conditions. To overcome these challenges, we developed a biodegradable supercapacitor incorporating iron single-atom catalysts anchored on carbonized bioinspired self-assembled architectures (Fe SA/cBSAs). Electrochemical experiments and density functional theory (DFT) calculations revealed that the single-atom Fe sites not only introduced additional pseudocapacitance via the reversible Fe3+/Fe2+ redox pair but also weakened the Na─O interaction through surface-potential redistribution, accelerating Na+ desorption and diffusion. This dual mechanism—combining enhanced redox activity with weakened Na+ binding—intensifies capacitive kinetics to synergistically improve both faradaic and electric-double-layer charge storage efficiencies, thereby yielding a marked increase in areal capacitance, energy density, and voltage stability without compromising charge-discharge rate capability. Fabricated using a polyvinyl alcohol/phosphate-buffered saline (PVA/PBS) hydrogel electrolyte and polylactic acid (PLA) encapsulation, the device exhibited excellent biocompatibility and outstanding biodegradability in vivo. In a murine inflammatory pain model, electrical stimulation delivered at the ST36 acupoint via our biodegradable supercapacitor markedly alleviated pain behavior and reduced inflammatory markers, confirming its therapeutic potential.

AB - Biodegradable supercapacitors represent a promising alternative to conventional power sources for implantable electrical stimulation therapies. However, their development has been impeded by the lack of electrode materials that simultaneously offer high-density redox-active sites, efficient charge transport, and biocompatibility under physiological conditions. To overcome these challenges, we developed a biodegradable supercapacitor incorporating iron single-atom catalysts anchored on carbonized bioinspired self-assembled architectures (Fe SA/cBSAs). Electrochemical experiments and density functional theory (DFT) calculations revealed that the single-atom Fe sites not only introduced additional pseudocapacitance via the reversible Fe3+/Fe2+ redox pair but also weakened the Na─O interaction through surface-potential redistribution, accelerating Na+ desorption and diffusion. This dual mechanism—combining enhanced redox activity with weakened Na+ binding—intensifies capacitive kinetics to synergistically improve both faradaic and electric-double-layer charge storage efficiencies, thereby yielding a marked increase in areal capacitance, energy density, and voltage stability without compromising charge-discharge rate capability. Fabricated using a polyvinyl alcohol/phosphate-buffered saline (PVA/PBS) hydrogel electrolyte and polylactic acid (PLA) encapsulation, the device exhibited excellent biocompatibility and outstanding biodegradability in vivo. In a murine inflammatory pain model, electrical stimulation delivered at the ST36 acupoint via our biodegradable supercapacitor markedly alleviated pain behavior and reduced inflammatory markers, confirming its therapeutic potential.

KW - biodegradable supercapacitor

KW - bioinspired self-assembly

KW - electrostimulation

KW - implantable bioelectronics

KW - single-atom catalyst

UR - https://www.scopus.com/pages/publications/105034753844

U2 - 10.1002/adfm.75184

DO - 10.1002/adfm.75184

M3 - Article

AN - SCOPUS:105034753844

SN - 1616-301X

VL - 36

JO - Advanced Functional Materials

JF - Advanced Functional Materials

IS - 44

M1 - e75184

ER -