A Rigid-Flexible Protecting Film with Surface Pits Structure for Dendrite-Free and High-Performance Lithium Metal Anode

Abstract

An artificial organic/inorganic composite protecting film for lithium metal anode with one-side surface pits structure was prepared by poly­(vinylidene fluoride-co-hexafluoropropylene) and Al2O3+LiNO3 inorganic additives. Due to the unique surface structure, the composite film can not only serve as an artificial protective film, but also act as an additional lithium plating host, which synergistically enabled the lithium metal anode to adapt to high current densities meanwhile maintain dendrite-free during long-term cycling. As a result, the protected lithium metal anode can operate stably for 1000 h at a high current density of 10.0 mA cm–2. When paired with a LiFePO4 or sulfur cathode, the full cells with unflooded electrolyte showed significantly improved cycling performance, demonstrating great potential of this artificial protecting film in lithium metal batteries.

Rationalized design of hyperbranched trans-scale graphene arrays for enduring high-energy lithium metal batteries

“…S22, where the charge/discharge plateaus are well retained during cycling without obvious increase in overpotential. When comparing with the recently reported Li metal full cells (14,16,19,(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52), the Li-HVDG||LFP cell in this work is more appropriately positioned at a high areal capacity, low N/P ratio, and low E/C ratio (Fig. 6D and table S1), highly desirable for achieving a high practical energy density.…”

Understanding Lithium Dendrite Suppression by Hybrid Composite Separators: Indentation Measurements Informed by Operando X-ray Computed Tomography

“…One strategy is to leverage the high ionic conductivity and strong modulus of inorganic fillers within an organic matrix . Several works simply disperse particles in gel separators and coatings, while others utilize covalent bonds and interactions between organic and inorganic phases to maximize spatial uniformity. ,− A prevalent duo in the hybrid inorganic–organic literature is filling poly­(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) with active (e.g., lithium-containing) inorganic particles, which together comprise an ionically conductive separator, coating, or electrolyte. ,− Several studies show that an optimal inorganic content exists to maximize the ionic conductivity of the material and the performance of the lithium metal battery. − Improvement of mechanics is also cited as a reason to incorporate the particles. However, mechanical experiments are often underappreciated in these works.…”

“…However, mechanical experiments are often underappreciated in these works. The mechanical experiments either apply deformation on the macroscale such as with tensile testing or on the nanoscale such as with atomic force microscopy (AFM). ,,,,, While these deformation length scales do occur at the lithium metal interface, the relevant length scales of lithium dendrite protrusions that result in soft shorting are not captured in these experiments.…”

Regulating the MXene–Zinc Interfacial Structure toward a Highly Revisable Metal Anode of Zinc–Air Batteries

“…Owing to superior theoretical specific capacity (820 mAh g –1 , 3694 Ah L –1 ), cost-effectiveness, high operational safety, and low redox potential (−0.76 V vs a standard hydrogen electrode) of Zn metal anodes, aqueous Zn batteries have attracted significant attention in large-scale energy storage community. − Particularly, rechargeable Zn–air batteries (ZABs) can deliver an ultrahigh energy density of 500 Wh kg cell –1 (1400 Wh L cell –1 ), which is approximately two times that of Li ion batteries (350 Wh kg cell –1 and 810 Wh L cell –1 ) and thus being hailed as the most promising next-generation battery system. , More advantageously, flexible ZABs are able to suppress short circuits and metal corrosion during repeated bending, showing great potential for wearable energy storage devices . In spite of these merits, several issues associated with Zn metal anodes in the strong alkaline condition, such as passivation, corrosion, dendrite growth, morphology change, and competing hydrogen evolution reaction (HER), seriously limit the practical performance of ZABs. − Therefore, it is urgent to regulate the anode structure and/or electrode–electrolyte interface structure toward enhanced stability of the Zn metal anode.…”