Mechano‐Electrochemically Promoting Lithium Atom Diffusion and Relieving Accumulative Stress for Deep‐Cycling Lithium Metal Anodes

Abstract

Lithium metal batteries (LMBs) can double the energy density of lithium‐ion batteries. However, the notorious lithium dendrite growth and large volume change are not well addressed, especially under deep cycling. Here, an in–situ mechanical–electrochemical coupling system is built, and it is found that tensile stress can induce smooth lithium deposition. Density functional theory (DFT) calculation and finite element method (FEM) simulation confirm that the lithium atom diffusion energy barrier can be reduced when the lithium foils are under tensile strain. Then tensile stress is incorporated into lithium metal anodes by designing an adhesive copolymer layer attached to lithium in which the copolymer thinning can yield tensile stress to the lithium foil. Elastic lithium metal anode (ELMA) is further prepared via introducing a 3D elastic conductive polyurethane (CPU) host for the copolymer–lithium bilayer to release accumulated internal stresses and resist volume variation. The ELMA can withstand hundreds of compression‐release cycles under 10% strain. LMBs paired with ELMA and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode can operate beyond 250 cycles with 80% capacity retention under practical condition of 4 mAh cm−2 cathode capacity, 2.86 g Ah−1 electrolyte‐to‐capacity ratio (E/C) and 1.8 negative‐to‐cathode capacity ratio (N/P), five times of the lifetime using lithium foils.

Synergistic Effect of CO2 in Accelerating the Galvanic Corrosion of Lithium/Sodium Anodes in Alkali Metal–Carbon Dioxide Batteries

“…However, the influence of the metal microstructures on their corrosion behaviors remains mostly unexplored in the alkali metal–CO 2 battery community . This is also true for the influence of the residual mechanical stress/strain within the alkali metal on their corrosion behaviors. In addition, the currently observed different sizes of the formed voids/cavities in the Li and Na interphase layer suggest that each metal has its own typical characteristics such as the distinct microscopic characteristics , (e.g., surface energy, self-diffusion barrier, etc.…”

Advancing the Manufacture of Metal Anodes for Metal Batteries

“…Metal anodes involve alkali metals (Li, Na, and K) and multivalent metals (Mg, Ca, Zn, and Al), and they are usually utilized in the form of metal foils. However, the practical application of metal anodes is accompanied by notorious challenges such as safety risks induced by metal dendrite growth, low Coulombic efficiency (CE) caused by parasitic reactions and “dead metal”, unstable solid electrolyte interphase (SEI), and low utilization of metal anodes due to their excessive thicknesses …”

“…However, the practical application of metal anodes is accompanied by notorious challenges such as safety risks induced by metal dendrite growth, low Coulombic efficiency (CE) caused by parasitic reactions and "dead metal", unstable solid electrolyte interphase (SEI), and low utilization of metal anodes due to their excessive thicknesses. 3 The intrinsic properties of metal anodes, including geometric structure, surface roughness, crystal orientation, grain size, defect, etc., are closely related to the manufacturing process. These properties play a decisive role in determining the electrochemical performance of metal anodes.…”

Ultra‐Sleek High Entropy Alloy Tights: Realizing Superior Cyclability for Anode‐Free Battery

“…[14][15][16][17] However, Li anodes with high Li content can cause low Li utilization (typically < 10%) and eventually degrade the energy density of the whole LIB device. [18][19][20] Recently, anode-free battery architecture completely eliminates the excess of active Li by pairing only Li-rich cathodes with a bare metal current collector, thereby endowing the full cell with the highest specific energy and energy density. [21,22] However, there are no artificial laden active Li sources to increase the affinity between the anode and Li during cycling in anode-free batteries, which will exacerbate Li dendrite growth.…”

“…[ 14–17 ] However, Li anodes with high Li content can cause low Li utilization (typically < 10%) and eventually degrade the energy density of the whole LIB device. [ 18–20 ]…”