Beneficial Effect of Li5FeO4 Lithium Source for Li-Ion Batteries with a Layered NMC Cathode and Si Anode. Issue 16 (23rd December 2020)

• Record Type: Journal Article
• Authors: Dose, Wesley M.; Villa, Cesar; Hu, Xiaobing; Dunlop, Alison R.; Piernas-Muñoz, Maria Jose; Maroni, Victor A.; Trask, Stephen E.; Bloom, Ira; Dravid, Vinayak; Johnson, Christopher S.
• Is Part Of: Journal of the Electrochemical Society. Volume 167:Issue 16(2020)
• Publication Date: 2020-12-23
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/abd1ef
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The energy density of lithium-ion batteries can be increased by replacing the traditional graphite anode with a high capacity silicon anode. However, volume changes and interfacial instabilities cause a large irreversible capacity and a continual loss of lithium during cycling, which lead to rapid capacity loss. In this work, we add Li5 FeO4 (LFO) to a LiNi0.5 Mn0.3 Co0.2 O2 (NMC) cathode as a pre-lithiation additive, which increases the lithium inventory and extends the cycle life of Si-graphite/NMC full cells, and decreases the NMC particle degradation. LFO delivers a large 764 mAh g −1 LFO capacity below 4.7 V vs Li/Li + . By tuning the LFO content in Si-graphite/LFO-NMC full cells, we show higher capacity, improved retention, lower impedance, and superior rate performance compared to full cells without LFO. Post-test characterizations demonstrate that LFO inclusion in the cathode matrix leads to less NMC secondary particle segregation/cracking and a thinner surface reduced layer on the NMC particles. The beneficial effects of LFO endure after the lithium reserve has been exhausted, highlighting a lasting synergy between the lithium source and electrode active materials. This study introduces a new approach to simultaneously increase lithium inventory and reduce cathode degradation, and makes critical advances toward enabling Si anodes for lithium-ion batteries.