Inverted Anode Structure for Long-Life Lithium Metal Batteries

Unlimited growth of lithium dendrites is undesirable yet preventing this still remains a challenge for pursuing high-energy battery systems. Serious safety hazards caused by short circuit and fire demand accurate control of the nucleation location of lithium deposition. Here, an inverted anode structure enabled by simple flipping of carbon fabric after lithium electrodeposition is reported. In contrast to traditional strategies of using regular upright structure, the inverted anode structure can guide a directional deposition of lithium to the bottom of the anode. The low nucleation barrier originating from the bottom lithium metal can induce a superior bottom-up deposition process. Lithium dendrite issues can thus be significantly alleviated, and approximately twice the cycle life extension of the lithium metal anode is achieved. More importantly, the solid electrolyte interphase immersed in the inverted anode structure is extremely stable, resulting from the well supporting skeleton of the surrounding carbon fabric fibers. The assembled lithium metal batteries show excellent cycling stability with a capacity retention per cycle of 99.98%, i.e., the battery capacity still retains 82.3% after 750 charge/discharge cycles. This simple inversion strategy is universal and can be extended to other porous current collectors, such as thin conductive fabric, and offers great opportunities for next-generation lithium-based batteries.