Self-assembly of hierarchical Ti3C2Tx-CNT/SiNPs resilient films for high performance lithium ion battery electrodes

In this work, flexible free-standing Ti3C2Tx-CNT/SiNPs (Si nanoparticles) resilient films with hierarchical pore are prepared by a simple and scalable self-assembly method. The Ti3C2Tx 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) Ti3C2Tx 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 Ti3C2Tx 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 Ti3C2Tx-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 Ti3C2Tx-CNT/SiNPs film anode is demonstrated, showing promising preliminary electrochemical performance and indicating the future application prospect in flexible LIBs.