Self-assembly of hierarchical Ti₃C₂T_x-CNT/SiNPs resilient films for high performance lithium ion battery electrodes

In this work, flexible free-standing Ti₃C₂T_x-CNT/SiNPs (Si nanoparticles) resilient films with hierarchical pore are prepared by a simple and scalable self-assembly method. The Ti₃C₂T_x nanosheets and acidified CNTs are attracted by hydrogen bonds via surface functional groups, and are further assembled with positively charged SiNPs modified by cetyltrimethyl-ammonium bromide via the electrostatic attraction. The subtle assembling and synergistic action among 0 dimensional (0D) SiNPs - 1 dimensional (1D) CNTs and 2 dimensional (2D) Ti₃C₂T_x nanosheets offer the films with excellent mechanical flexibility, conductivity, abundant hierarchical voids and thus superior and impressive electrochemical properties as binder-free LIBs anode. The hierarchical pore structure effectively inhibits both the aggregation of SiNPs and restacking of Ti₃C₂T_x nanosheets, provides fast electron and ion diffusion path, facilitates the penetration of electrolyte and absorbs the volume expansion of SiNPs during the charge and discharge processes. The Ti₃C₂T_x-CNT/SiNPs film exhibits a high areal capacities up to 5.2 mAh cm⁻² at the current density of 100 mA g⁻¹. Moreover, a good cyclic retention of 2.2 mAh cm⁻² at an area mass loading of 2.3 mg cm⁻² after 150 cycles is also achieved. Furthermore, a pouch cell based on the Ti₃C₂T_x-CNT/SiNPs film anode is demonstrated, showing promising preliminary electrochemical performance and indicating the future application prospect in flexible LIBs.