Composite Anode Interlayers for Lithium Batteries with Stable Anode-Electrolyte Interfaces Under High Charging Current Densities

75976-In the rechargeable lithium batteries that are targeted for use with electric and hybrid electric vehicles, the use of lithium metal directly as the anode could provide higher voltage and higher capacity. However, the principal impediment using these lithium metal anodes is the occurrence of lithium dendrite growth during charging, which limits both the maximum current density that can be imposed and the number of cycles. It can be shown theoretically and experimentally that the greater the resistance to charge transfer at the anode/electrolyte interface, the greater the tendency for dendrite growth. This project will develop technology for modifying the anode/electrolyte interface by introducing composite, electrochemically active interlayers, which effectively lower the charge transfer resistance, thereby drastically lowering the propensity for dendrite growth. In Phase I, the role of the anode/electrolyte charge transfer resistance on dendrite growth will be theoretically addressed by solving the requisite mixed boundary value problem for various values of the charge transfer resistance, which correspond to the situation with and without composite interlayers. Li-electrolyte-Li and Li-electrolyte-cathode cells will be made, with and without the composite electrode interlayers, and their electrochemical performance will be experimentally measured to determine whether incorporating the composite layers improves resistance to dendrite growth. Commercial Applications and Other Benefits as described by the awardee: Lithium rechargeable cells that can use direct lithium metal anodes without degradation should lead to increased capacity, both in terms of Amph/kg and Wh/kg, making them viable candidates for electric vehicles.