Harvesting High Loading Electrode with Nanosized Particles for Rechargeable Lithium Batteries

Contributed by significantly improved solid/liquid interface and kinetics of Li⁺  diffusion, nanostructured electrode materials offer wide and promising applications in Li-ion and rechargeable lithium batteries, especially for the high power demand.^[1] For example, by embedding electronic insulating sulfur into the nanostructured carbon frameworks, the obtained sulfur/carbon composites deliver high capacity and greatly improved cycling stability as cathode.^{[2, 3]} Similarly, silicon exhibits outstanding properties as promising anode for Li-ion batteries after reduced to nanosize or combined with carbon by forming Si/C composites.^[4] Despite these superiorities of nanosized novel structures, materials in nano-scale still face the challenge with respect to the practical applications in batteries. Besides side reactions initiating on the high surface electrode, it is difficult to achieve high loading electrode with nanosized active materials through slurry coating technique due to the generation of sever cracking or pinholes during the drying process. One of the reasons behind this phenomenon is the large volume shrink of nanosized materials accompanying the solvent removing from slurry. These downsides have plagued the practical application of nano-sized materials in energy storage systems. Attempts have been made to address these issues by increasing the particle size through spray drying, introducing conductive polymer or other self-assemble approaches, which are either complicated with special equipment or not cost-effective for large scale applications. We herein propose a facile and up-scale available approach to coat nano particles into electrodes with practically usable thickness and active mass loadings. Successful demonstration of this approach was shown in sulfur and silicon nano particles. High loading but crack-free coating for sulfur (loading: 2-8 mg sulfur/cm²) and Si (loading: 2-4 mg Si/ cm²) electrodes have been displayed. In addition, we did detailed screen for the binder selection and slurry composition modification. Base on the obtained high loading electrodes, systematical study was performed on the relationships of electrode loading, pressure, energy density and rate capability. All these obtained results will be presented at the meeting.

References

[1]          A. S. Arico; P. Bruce; B. Scrosati; J. M. Tarascon; W. Van Schalkwijk, Nature Materials 2005, 4, 366.

[2]          X. Ji; K. T. Lee; L. F. Nazar, Nature Materials 2009, 8, 500.

[3]          J. Zheng; M. Gu; M. J. Wagner; K. A. Hays; X. Li; P. Zuo; C. Wang; J.-G. Zhang; J. Liu; J. Xiao, Journal of the Electrochemical Society 2013, 160, A1624.

[4]          C. K. Chan; H. Peng; G. Liu; K. McIlwrath; X. F. Zhang; R. A. Huggins; Y. Cui, Nature Nanotechnology 2008, 3, 31.