Mechanically Robust, Highly Conductive, Wide‐Voltage Cellulose Ionogels Enabled by Molecular Network Reconstruction

Abstract Cellulose ionogels gain considerable attention for their application in flexible electronic devices. However, achieving an optimal balance between their mechanical and electronic properties remains a challenge. Here, a high‐performance cellulose ionogel is reported through strengthening the hydrogen bond network and weakening electrostatic interactions within cellulose molecular framework. The resulting ionogels, under a single molecular network, exhibit impressive tensile strength of 3.5 MPa and ionic conductivity of 14.3 mS cm ⁻¹ . Additionally, they demonstrate a wide voltage window of up to 3.0 V and high thermal stability, withstanding temperatures exceeding 120 °C. Serving as all‐solid electrolytes, the ionogels contribute to the construction of integrated flexible energy storage devices, achieving a remarkable energy density of over 60 Wh kg⁻¹ and demonstrating significant cycle stability, with a capacitance retention rate exceeding 97% after 10 000 charge–discharge cycles. With the robust mechanical and electrical properties, the cellulose ionogel is well‐positioned to offer innovative insights for the next generation of flexible, integrated electronic devices.