Nanostructure Electrodes for 3D Li-ion Microbatteries
2008 (English)In: Junior Euromat 2008 14-18 July, Lausanne (CH) oral presentation, 2008Conference paper (Other (popular scientific, debate etc.))
The vast development of surface micromachining technology has brought the proliferation of MEMS devices. However, the issue of powering the MEMS devices still remains as a great challenge. Although the conventional thin film 2D batteries seems promising for achieving high power density, however, relatively large area is required for having sufficient capacity. The drawbacks of 2D batteries can be overcome by using 3D architecture of Li-ion microbatteries.
The 3D architecture of Li-ion microbatteries will have the advantages of short diffusion path as the electrode active materials are just tenth of nanometer deposited on the current collectors. The short diffusion path guarantees the high power performance. Besides that, the capacity of the microbatteries can be enhanced by just increasing the length of the electrode while keeping the areal footprint. This is what makes the 3D microbatteries a more promising power supply for MEMS.
Our approach to synthesize a 3D Li-ion microbattery is starting with the synthesis of a nanostructure current collector using a template method. An anodized aluminium oxide (AAO) membrane is used as template for the electrodeposition of an aluminium current collector. AAO with defined pore sizes and inter-pores spacing are synthesized with a suitable diameter and interspacing where an aluminium current collector can grow within the template. The following step is the deposition of electrode active materials on the current collector. In this example Atomic Layer Deposition (ALD) is employed in order to achieve a well deposited layer of, in this case, a TiO2 cathode material. By controlling the deposition parameters, the crystal structure and the thickness of TiO2 layer can be altered to give a better electrochemical performance. Our results will be discussed in the light of the complexity of the deposition mechanisms of both the aluminium current collector nano-rods and the TiO2 layer.
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IdentifiersURN: urn:nbn:se:uu:diva-17455OAI: oai:DiVA.org:uu-17455DiVA: diva2:45226