# High‐Performance Printed Supercapacitors Based on NaOH‐Activated Wood‐Derived Carbon: Optimized Porosity and Long‐Term Stability in Aqueous Electrolytes

## TL;DR

This paper presents a sustainable method to create high-performance supercapacitors using wood-derived carbon with optimized porosity and long-term stability.

## Contribution

A low-temperature NaOH activation method is introduced to tailor biomass-derived carbon for superior supercapacitor performance.

## Key findings

- AWC 3-600 achieves ≈307 F g⁻¹ capacitance in NaCl and retains 95% after 10,000 cycles.
- Microporous AWC 3-600 works best with NaCl, while mesoporous AWC 4-700 suits KxHyPO4.
- The method enables tunable electrochemical behavior in biomass-derived carbons.

## Abstract

The transition to sustainable energy technologies calls for supercapacitors that are not only efficient but also environmentally responsible. In this work, a step towards solving this challenge is taken by applying a low‐temperature NaOH activation strategy to alder‐wood‐derived carbon. Such process generates an amorphous carbon matrix with thinly‐layered sheets of graphene‐like domains, facilitating efficient ion‐electron transport, as revealed through comprehensive material characterizations. Various carbon structures were obtained by adjusting the alkali‐to‐carbon ratio and activation temperature wherein the most effective is 3:1 ratio at 600 °C (AWC 3‐600). Its combined 2393 m2 g−1 surface area and 85.4% microporosity provides a pore architecture that works exceptionally well with aqueous electrolytes. When integrated into printed supercapacitors, it achieves ≈307 F g−1 in NaCl and ≈291 F g−1 in K
x
H
y
PO4. Even after 10,000 charge–discharge cycles, the devices retain 95% of their original capacitance, demonstrating long‐term stability. The results of this study highlights the strong interactions between the electrolyte and pore structure, where NaCl benefits from the microporous AWC 3‐600while K
x
H
y
PO4 performs better on the mesoporous structure obtained with an activation process of 4:1 ratio at 700 °C (AWC 4‐700). This study shows that low‐temperature NaOH activation offers an effective way to engineer biomass‐derived carbons with tunable electrochemical behavior.

A low‐temperature NaOH activation strategy tailors alder‐wood‐derived carbons into highly porous, graphene‐like structures for printed supercapacitors. The optimized AWC 3‐600 material delivers high capacitance and excellent cycling stability, outperforming commercial benchmarks. The work highlights the crucial role of electrolyte–pore matching and offers a scalable path toward sustainable, high‐performance energy storage.© 2026 WILEY‐VCH GmbH