Jiwon Jung

Development of miniaturized thin‐film lithium‐ion batteries (TF‐LIBs) using vacuum deposition techniques is crucial for low‐scale applications, but addressing low energy density remains a challenge. In this work, structures analogous to SiO x ‐based thin‐film electrodes are designed with close resemblance to traditional LIB slurry formulations including active material, conductive agent, and binder. The thin‐film is produced using mid‐frequency sputtering with a single hybrid target consisting of SiO x nanoparticles, carbon nanotubes, and polytetrafluoroethylene. The thin‐film SiO x /PPFC (plasma‐polymerized fluorocarbon) involves a combination of SiO x and conductive carbon within the PPFC matrix. This results 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 demonstrates 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 exhibits 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 stepping stone for the AM/CB/B composite electrodes in TF‐LIBs.