A Nanofibrillated Cellulose/Polyacrylamide Electrolyte‐Based Flexible and Sewable High‐Performance Zn–MnO₂ Battery with Superior Shear Resistance

There is a growing demand for flexible and wearable energy devices. How to enhance their tolerance to various mechanical stresses is a key issue. Bending, stretching, or twisting of flexible batteries has been widely researched. However, shear force is inevitably applied on the batteries during stretching, bending, and twisting. Unfortunately, thus far, research on analyzing shear resistance of solid batteries or even enhancing the shear tolerance has never been reported. Herein, a sewable Zn-MnO₂ battery based on a nanofibrillated cellulose (NFC)/ployacrylamide (PAM) hydrogel, electrodeposited Zn nanoplates anode, and carbon nanotube (CNT)/α-MnO₂ cathode is reported. The designed NFC/PAM hydrogel exhibits a relatively high mechanical strength with a large stretchability; the preformed NFC bone network stabilizes the large pores as channels for electrolyte diffusion. Furthermore, the effect of sewing on enhancing the shear resistance of the solid batteries is analyzed. The sewed Zn-MnO₂ battery retains 88.5% of its capacity after 120 stitches, and withstands a large shear force of 43 N. The sewable and safe Zn-MnO₂ is also able to be designed into a skirt and put on a toy as an energy source to power a red light emitting diode.