Constructing Self-Adapting Electrostatic Interface on Lithium Metal Anode for Stable 400 Wh kg-1 Pouch Cells

The realization of large-capacity, high-energy-density Li metal battery technology is seriously impeded by dendrite growth and massive dead lithium formation upon cycling. Here, a stable flexible electrostatic self-adapting polymer (poly(1-benzyl-3-vinylimidazolium), (PBM)) interface is reported to regulate lithium-ion deposition for dendrite-free lithium metal batteries. The cationic PBM interlayer can adaptively tune the surface current density near the lithium/electrolyte interface, inducing a uniform distribution of current density and lithium ions and thus achieving dendrite-free Li deposition under harsh conditions (lean electrolyte 8.75 mu L mAh(-1), high areal capacity >4 mAh cm(-2)). Moreover, the tethered phenyl groups endow PBM with a low reduction potential of -3.7 V versus standard hydrogen electrode by decreasing Hirshfeld charge at the reductive site. This avoids electrochemical reduction and therefore ensures the long-term stability of the PBM interface. Consequently, the Li|PBM@Cu asymmetric cells deliver a high average Coulombic efficiency of 99.38% at 8 mAh cm(-2) with lean electrolyte. Notably, the 5.1 Ah LiNi0.8Co0.1Mn0.1O2|PBM@Li pouch cell exhibits excellent cycling stability (0.011% decay/cycle) and high energy density (418.7 Wh kg(-1)) under realistic conditions (lean electrolyte 2.5 g Ah(-1), high areal capacity 5.7 mAh cm(-2), and high current density 2.7 mA cm(-2)).

Automated summary

The stable and flexible electrostatic self-adapting PBM interface effectively regulates lithium-ion deposition to achieve dendrite-free lithium metal batteries under harsh conditions, with high Coulombic efficiency and cycling stability. The PBM interface also features a low reduction potential and long-term stability, enabling high energy density and cycling stability in realistic conditions.