Lithium-ion battery testing. (Credit: Argonne National Laboratory)Scientists at the University of Tokyo have developed an approach with industrial potential to produce nano-sized composite silicon-based powders as negative electrodes for the next generation lithium ion batteries.
The lithium-ion battery market has been growing steadily and has been seeking an approach to increase battery capacity while retaining its capacity for long recharging process.
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Field emission scanning electron microscope (FE-SEM) images of the raw SiO (a), plasma sprayed (PS-PVD) powder with CH4 addition (C/Si = 1) (b) and its higher magnification. (Credit: See citation at the end of this article)
Structuring materials for electrode at the nanometer-length scale has been known to be an effective way to meet this demand; however, such nanomaterials would essentially need to be produced by high-throughput processing in order to transfer these technologies to industry.
In a new article published in Science and Technology of Advanced Materials (see footnote), scientists report an industrially compatible high-throughput approach to the production of nano-sized composite silicon-based powders that can be used as negative electrodes for the next generation high-density lithium-ion batteries.
The authors have successfully produced nanocomposite SiO powders by plasma spray physical vapor deposition using low-cost metallurgical grade powders. Using this method, they demonstrated an explicit improvement in the battery capacity cycle performance with these powders as an electrode.
The uniqueness of this processing method is that nanosized SiO composites are produced instantaneously through the evaporation and subsequent co-condensation of the powder feedstock. The approach is called plasma spray physical vapor deposition (PS-PVD).
The composites are 20 nm particles, which are composed of a crystalline Si core and a SiOx shell. Furthermore, the addition of methane (CH4) promotes the reduction of SiO and results in a decreased SiO-shell thickness. The core-shell structure is formed in a single-step continuous processing.
As a result, half-cell batteries made of PS-PVD powders have exhibited improved initial efficiency and were able to maintain capacities as high as 1000 mAh g−1 after 100 cycles.
Homma, K., Kambara, M., & Yoshida, T. (2014). High throughput production of nanocomposite SiO powders by plasma spray physical vapor deposition for negative electrode of lithium ion batteriesScience and Technology of Advanced Materials, 15 (2) DOI: 10.1088/1468-6996/15/2/025006
