Towards Improving the Practical Energy Density of Li-Ion Batteries: Optimization and Evaluation of Silicon:Graphite Composites in Full Cells. Issue 1 (31st December 2016)

• Record Type: Journal Article
• Authors: Yim, Chae-Ho; Niketic, Svetlana; Salem, Nuha; Naboka, Olga; Abu-Lebdeh, Yaser
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 1(2017)
• Page Start: A6294
• Page End: A6302
• Publication Date: 2016-12-31
• Subjects: Composite -- energy density -- Energy storage -- Full cell -- Li-ion -- Silicon; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0481701jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Increasing the energy density of Li-ion batteries is very crucial for the success of electric vehicles, grid-scale energy storage, and next-generation consumer electronics. One popular approach is to incrementally increase the capacity of the graphite anode by integrating silicon into composites with capacities between 500 and 1000 mAh/g as a transient and practical alternative to the more-challenging, silicon-only anodes. In this work, we have calculated the percentage of improvement in the capacity of silicon:graphite composites and their impact on energy density of Li-ion full cell. We have used the Design of Experiment method to optimize composites using data from half cells, and it is found that 16% improvements in practical energy density of Li-ion full cells can be achieved using 15 to 25 wt% of silicon. However, full-cell assembly and testing of these composites using LiNi0.5 Mn0.5 Co0.5 O2 cathode have proven to be challenging and composites with no more than 10 wt% silicon were tested giving 63% capacity retention of 95 mAh/g at only 50 cycles. The work demonstrates that introducing even the smallest amount of silicon into graphite anodes is still a challenge and to overcome that improvements to the different components of the Li-ion battery are required.