All-In-One Stainless-Steel Mesh Oxide Composites Anode for Flexible Li-Ion Battery

For portable and wearable electronics, a flexible full battery can lead to tremendous development. However, certain issues with the anode still exist, such as complexity, low capacity, and poor stability. Herein, a flexible metal oxide (MOx) composite anode is synthesized in situ, which transfers a stainless-steel mesh (SSM) to the SSM-MOx-900@PPy anode, with void-array MOx nanoframeworks encapsulated within polypyrrole (PPy). The hierarchical structure offers a close connection and highly interpenetrated porous conductive network between PPy and MOx, which sufficiently constrains the volume changes and enhances the electronic conductivity. Besides, the binder-free connection between the active material and current collector is effective for charge transport and robust structural stability during the electrochemical processes. The prepared SSM-MOx@PPy anode exhibits low contact resistance, decreased charge transfer resistance, and enhanced Li⁺ diffusion coefficient, resulting in an ultrahigh capacity of 1000 mAh g⁻¹ at 0.1 C and outstanding cycling stability of 640.9 mAh g⁻¹ with a retention rate of 99% after 100 cycles at 1 C. The high-power full battery fabricated by the SSM-MOx-900@PPy and LiFePO₄ can be bent and folded freely without obvious capacity attenuation (99.2% of the initial value after 100 bending cycles). These results may provide valuable guidance for designing advanced anodes.