Carbon additive effect on the electrochemical performances of inkjet printed thin-film Li4Ti5O12 electrodes

Conventional rigid batteries find limited applications in the wearable and flexible electronics field, as difficulties in device integration due to lack of shape conformability to unconventional substrates remain an obstacle. Accordingly, new fabrication techniques are under investigations and printing techniques have attracted great interest for their selectivity, low material waste and scalability. In this frame, inkjet printing (IJP) has emerged as a potential fabrication technique to obtain flexible patterned thin-film electrodes with high resolution. However, a more in-depth systematic study of how IJP can be applied to lithium-ion batteries fabrication is still missing. Herein, we propose a study that focuses on how different carbon-based additives (Nitta et al., 2015; Choi and Ahn, 2018 [1,2]), i.e. carbon black and multi-walled carbon nanotubes, affect the electrochemical performances of inkjet printed thin-films Li4Ti5O12 electrodes. A simple ink formulation is proposed, which is aqueous-based, non-toxic and safe to handle. The fabricated thin-film electrodes showed different specific capacity, the highest associated with the carbon nanotubes-based (CNTs) electrode, i.e. 150.3 mAh g−1 at 0.2 C, showing that CNTs improving electrochemical performances can be applied also to printed electrodes. The carbon nanotubes-based electrodes showed excellent cycle stability, with negligible capacity loss for over 100 cycles. The work highlights the importance of a valid material choice to reach the desired electrode performances and may inspire alternatives paths to deepen IJP of lithium-ion batteries fabrication.