Mildly Turbostratic Films based on Defect‐Less Ti3C2Tx MXene with Ultrahigh Volumetric Capacitance for Electrochemical Zinc‐Ion Storage

Abstract The practical deployment of electrochemical zinc‐ion storage devices in compact electronics requires electrodes with high volumetric energy density and structural integrity. Vacuum‐filtrated 2D conductive MXenes inherently support dense packing, ensuring the volumetric performance and structural robustness. However, their application is hindered by the intrinsic defects in MXenes and c ‐axis ordering, both of which restrict ion transport and reversibility. Here, a facile lithium chloride (LiCl) treatment protocol before vacuum filtration process of Ti 3 C 2 T x Mxene is reported. This induces local wrinkling that disrupts long‐range stacking while preserving short‐range order along c ‐axis of the free‐standing Ti 3 C 2 T x assemblies, thereby facilitating through‐plane ion diffusion without compromising the electrode density. Simultaneously, Li + passivates the defects of Ti 3 C 2 T x , thereby enhancing electrochemical reversibility. The free‐standing electrodes for electrochemical zinc‐ion storage deliver a record‐high volumetric capacitance of 560.8 F cm −3 , retain 70% capacitance at 20 A g −1 , and exhibit 100.9% retention over 50,000 cycles. Notably, a flexible device using the customized film electrode maintains performance under extreme deformation, achieving an energy density of 60.6 Wh L −1 at an ultrahigh power density of 42,779 W L −1 . This work offers a scalable, MXene‐focused strategy that bridges dense film assembly with ion‐accessible architecture, enabling advanced energy storage for size‐constrained and deformable devices.