Modulating electrode utilization in lithium-ion cells with silicon-bearing anodes

JOURNAL OF POWER SOURCES

卷:477

Article

Rodrigues, Marco-Tulio F.¹  Prado, Andressa Y. R.¹  Trask, Stephen E.¹  Ahmed, Shabbir¹  Jansen, Andrew N.¹  Abraham, Daniel P.¹ 

[1] Argonne Natl Lab, Chem Sci & Engn Div, Argonne, IL 60439 USA

关键词: N/P ratio;    Cell balancing;    Capacity;    Impedance;    BatPaC;    Dilatometry;   

DOI  :  10.1016/j.jpowsour.2020.229029

来源: Elsevier

【 摘 要 】

The stability of silicon-containing anodes can, in principle, be extended by constraining these electrodes to limited states of lithiation. Partial utilization of the anode lessens the volume changes experienced by silicon particles during cycling, which can mitigate mechanisms of performance degradation. In full-cells, anode utilization can be modulated by adjusting the relative capacities of the negative and positive electrodes - the N/P ratio. Here, we examine how the N/P ratio affects the long-term stability of Si-based full-cells, and investigate how this parameter would impact the cost and energy of realistic Li-ion cells. We show that, for some configurations, cell failure due to rapid anode degradation can only by avoided at higher N/P ratios. The price of this enhanced stability is accelerated impedance rise at the cathode. Surprisingly, when electrode expansion is taken into account, increasing N/P ratio can actually increase the specific energy and energy density of silicon-rich Li-ion cells.

【 授权许可】

Free