Analogous Design of a Microlayered Silicon Oxide-Based Electrode to the General Electrode Structure for Thin-film Lithium-Ion Batteries.

Development of miniaturized thin-film lithium-ion batteries (TF-LIBs) using vacuum deposition techniques are crucial for low-scale applications, but addressing low energy density remains a challenge. In this work, we designed structures analogous to SiO x -based thin-film electrodes with close resemblance to traditional LIB slurry formulations including active material, conductive agent, and binder. The thin-film was produced using mid-frequency (MF) sputtering with a single hybrid target consisting of SiO x nanoparticles, carbon nanotubes, and polytetrafluoroethylene (PTFE). The thin-film SiO x /PPFC involved a combination of SiO x and conductive carbon within the plasma-polymerized fluorocarbon (PPFC) matrix. This resulted in enhanced electronic conductivity and superior elasticity and hardness in comparison to a conventional pure SiO x -based thin-film. The electrochemical performance of the half-cell consisting of thin-film SiO x /PPFC demonstrated remarkable cycling stability, with a capacity retention of 74.8% up to the 1000th cycle at 0.5 C. In addition, a full cell using the LiNi 0.6 Co 0.2 Mn 0.2 O 2 thin-film as the cathode material exhibited an exceptional initial capacity of ∼120 mAh g -1 at 0.1 C and cycle performance, marked by a capacity retention of 90.8% from the first cycle to the 500th cycle at a 1 C rate. This work will be a steppingstone for the AM/CB/B composite electrodes in TF-LIBs. This article is protected by copyright. All rights reserved.