Perpustakaan Digital ITB

Three-dimensional (3D) thin-film solid-state batteries are aninteresting concept for microstorage, promising high footprint capacity, fast charging,safety, and long lifetime. However, to realize their commercialization, severalchallenges still need to be overcome. In this work, we focus on two issues: theconformal coating and the high throughput deposition of thin-film layers. First, tofacilitate conformal deposition, a design based on 3D micropillars is chosen.Although such a design has been suggested in the past, we calculate for thefirst timewhat (footprint) capacities can be expected when using fully optimized pillargeometries while taking practical manufacturability into consideration. Next, spatialatomic layer deposition (S-ALD) is investigated as a scalable and conformal deposition technique. As proof-of-concept, 100 nmCl-doped am-TiO2thin-film electrodes are deposited by S-ALD on TiN-coated silicon micropillars. The influence of depositionparameters (i.e., exposure time and temperature) on the conformality and uniformity across the micropillar substrate isinvestigated. The results are discussed in terms of precursor diffusion and depletion, which is supported by an analytical modeldeveloped for our micropillar array. Furthermore, the Li-ion insertion properties of 3D electrodes fabricated by S-ALD andconventional ALD are compared. This research highlights the challenges and promises of 3D microbatteries and guides futureS-ALD development to enable conformal and high-throughput thin-film deposition.