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The Effect of Pre-Lithiation Chemistry on Li Inventory in High-Energy Li-Ion Cells

Sunday, 1 October 2017: 17:40
Chesapeake J (Gaylord National Resort and Convention Center)
W. M. Dose, P. Senguttuvan, J. Blauwkamp, and C. S. Johnson (Argonne National Laboratory)
Silicon containing anodes employed in Li-ion cells are known to dramatically boost the energy density of a full LIB battery by providing a high intrinsic capacity via LixSi intermetallic alloy formation/utilization compared to capacity-limited graphite anodes. However, because a >300% volume change takes place between (de)lithiated LixSi states, a irreversible trapping of cyclable Li in the full cell occurs, negatively impacting performance, potentially lowering cycle life. Moreover, electrode slippage happens whereby the lithium inventory in the battery is compromised, and less cathode capacity can be utilized. In this work we (1) first assess Li-inventory trends from the use of LiFePO4 thick electrodes versus thin 15%Si•graphite anodes, (2) evaluate chemically pre-lithiated 4-V and 5-V spinels in full cells, and (3) implement high-capacity (>700 mAh/g) lithium iron oxide Li5FeO4 anti-fluorite materials as a pre-lithiation additive in the cathode. We will report the findings of this study in this presentation.