Carbon nanotube-interlocked Si/CNF self-supporting electrode using continuable spraying architecture system for flexible lithium-ion batteries

To overcome the limitations of conventional rigid lithium-ion batteries (LIBs) for state-of-the-art multifunctional electronics applications, advanced electrode manufacturing processes are required based on the widely known slurry casting process on metal current collectors. The spraying architecture of an electrode is promising for developing high-performance self-supporting electrodes for flexible LIBs applications. Using a water-soluble and highly dispersed precursor solution containing carbon nanotubes (CNTs), silicon nanoparticles (Si NPs), and carbon nanofibers (CNFs), we report a novel strategy for the continuous preparation of flexible electrodes. Through the CNT interlocking network over the CNF framework and Si NP hybrid structure, the CNT-Si/CNF flexible electrode showed noticeable enhancement in mechanical, electrical, and electrochemical properties. The resultant CNT-Si/CNF demonstrated an excellent specific capacity of 1708.7 mAh/g together with the rapid energy storage kinetics (514.8 mAh/g at 2,000 mA/g). Moreover, the CNT-Si/CNF electrode retained its high specific capacity even after 3,000 flexibility test cycles. The pouch-type entire cell was also demonstrated by preparing the cathode part as CNT-LFP/CNF, which operated a 1.5 V light-emitting diode. Therefore, the continuous spraying-electrode architecture system and resultant CNT-Si/CNF flexible electrode can facilitate the technological development of the high-performance flexible energy source for the deformable electronics.