Preferentially oriented SrLi2Ti6O14 thin film anode for Li-ion micro-batteries fabricated by pulsed laser deposition

Highlights: • Crystalline and preferentially oriented SrLi₂Ti₆O₁₄ thin films were successfully deposited. • Structural and morphology studies confirm the growth mechanism of SrLi₂Ti₆O₁₄ thin films. • SrLi₂Ti₆O₁₄ thin films delivered a high capacity of 160 mAh.g⁻¹. To realize all-solid-state thin-film microbatteries, robust anode candidates play a key role. SrLi₂Ti₆O₁₄ forms one such Ti-based anode with ideal combination of electrochemical performance and operational safety. In the current work, SrLi₂Ti₆O₁₄ anode thin-films were deposited on stainless steel substrates by pulsed laser deposition technique. X-ray diffraction confirmed the crystallinity and phase-purity of these films with preferred orientation. They were found to have uniform thickness with homogeneous morphology as revealed by scanning electron and atomic force microscopy. These as-deposited thin-film anodes exhibited active electrochemical behavior, delivering a reversible capacity over 160 mAh.g⁻¹ without any carbon or conductive additives. Involving a Ti⁴⁺/Ti³⁺ redox activity around 1.4 V lying in the safe operational window of organic electrolytes, the SrLi₂Ti₆O₁₄ thin film forms a promising anode candidate for Li-ion micro-batteries.