Rational design of high conductivity and robust associativity aluminum current collector based on polyaniline for lithium-ion battery

Abstract

The interfacial interaction between active electrode materials and current collectors is a cornerstone in defining the electrochemical efficacy of lithium-ion batteries. In this investigation, we have designed a high conductivity and robust associativity aluminum current collector, through integrating a novel network-crater structure into the surface of aluminum current collector by adopting a hybrid technique that combines chemical etching, with the electrochemical polymerization of conductive polyaniline (PANI) films. Of particular interest, when the electrochemical polymerization cycle is optimized to 5 (P/E-Al-5), the resultant structure exhibits augmented wettability and an extraordinary interfacial adhesive strength, with a peel value of 417.0 N/m. This augmentation is ascribed to the synergistic influence of mechanical interlocking and chemical bonding at the interface between the aluminum current collector and the LiFePO₄ layers. Furthermore, the P/E-Al-5 current collector demonstrates commendable electrical conductivity, and the batteries incorporating this collector exhibit the least charge transport resistance. Consequently, the P/E-Al-5 current collector imparts enhanced electrochemical performance, distinguished by the highest rate capability and cycling stability. Impressively, at a high current rate of 5 C, the P/E-Al-5 collector manifests an average discharge capacity of 98.8 mAh g⁻¹, a 59 % improvement over the unmodified aluminum sample (62.0 mAh g⁻¹). Additionally, battery with the P/E-Al-5 current collector displays an elevated reversible discharge capacity, with a retention rate of 99.2 %. This study provides an inspiration for the design of high-performance aluminum current collector.