Anode‐Free Full Cells: A Pathway to High‐Energy Density Lithium‐Metal Batteries

The development of high‐energy density batteries is critical to the decarbonization of the transportation and power generation sectors. For any given lithium‐containing cathode system, the anode‐free full cell configuration, which eliminates excess lithium and pairs the fully lithiated cathode with a bare current collector, can deliver the maximum possible energy density. The absence of free lithium metal during cell assembly confers significant practical advantages as well. It is also the ideal framework for developing a thorough understanding of lithium deposition in conjunction with various cathode systems. However, the poor efficiencies of lithium plating and stripping lead to rapid lithium inventory loss and poor cycle life. In the last few years, multiple studies have demonstrated the application of advanced electrolytes, modified current collectors, and optimized formation and cycling parameters to stabilize lithium deposition and improve cycle life (80% capacity retention) to 100 cycles and beyond. This review provides an overview of the various strategies toward sustaining lithium inventory in anode‐free full cells and summarizes the work undertaken in this nascent field. It is expected that further improvement upon these strategies and a combinatorial approach can enable cycle lives far in excess of what has been achieved so far.