Electrochemically Dealloying Engineering toward Integrated Monolithic Electrodes with Superior Electrochemical Li‐Storage Properties

Abstract Integrated monolithic electrodes (IMEs) free of inactive components demonstrate great potential in boosting energy‐power densities and cycling life of lithium‐ion batteries. However, their practical applications are significantly limited by low active substance loading (< 4.0 mg cm ⁻² and 1.0 g cm ⁻³ ), complicated manufacturing process, and high fabrication cost. Herein, employing industrial Cu‐Mn alloy foil as a precursor, a simple neutral salt solution‐mediated electrochemical dealloying strategy is proposed to address such problems. The resultant Cu‐Mn IMEs achieve not only a significantly larger active material loading due to the in situ generated Cu ₂ O and MnO _x (ca. 16.0 mg cm ⁻² and 1.78 g cm ⁻³ ), simultaneously fast transport of ions and electrons due to the well‐formed nanoporous structure and built‐in Cu current collector, but also high structural stability due to the interconnected ligaments and suitable free space to relieve the volume expansion upon lithiation. As a result, they demonstrate remarkable performances including large specific capacities (> 5.7 mAh cm ⁻² ), remarkable pseudocapacitive effect despite the battery‐type constitutes, long cycling life, and good working condition in a lithium‐ion full cell. This study sheds new light on the further development of IMEs, enriches the existing dealloying techniques, and builds a bridge between the two.