Polymer-Stabilized Liquid Metal Nanoparticles as a Scalable Current Collector Engineering Approach Enabling Lithium Metal Anodes

Abstract

Dendrites and dead lithium formation over prolonged cycling have long been challenges that hinder the safe implementation of metallic Li anodes. Herein, we employ polymer-stabilized liquid metal nanoparticles (LM-P NPs) of eutectic gallium indium (EGaIn) to create uniform Li nucleation sites enabling homogeneous lithium electrodeposition. Block copolymers of poly­(ethylene oxide) and poly­(acrylic acid) (PEO-b-PAA) were grafted onto the EGaIn surface, forming stabilized, well-dispersed NPs. Using a scalable spray coating approach, LM-P NPs were fabricated on copper current collectors, providing lithiophilic PEO sites and interactive carboxyl groups to guide Li deposition. The Li-EGaIn alloying process greatly reduced the Li+ diffusion barrier, enabling fast Li transport through the coating layer, resulting in decreased nucleation overpotential. Therefore, about five times lower Li nucleation overpotential was obtained on the LM-P modified Cu with an optimal composition of the polymers than the bare Cu substrates. DFT computations was used to reveal the binding properties between the LM-P layer and Li. Due to the regulated Li plating/stripping process, as-obtained 30 μm Li anodes paired with LiNi0.8Co0.1Mn0.1O2 (NCM811) with a negative/positive electrode capacity (N/P) ratio ∼ 10 exhibited stable cycling performance at 0.5C for over 250 cycles, with an average Coulombic efficiency of 99.55%. Ultrathin Li (1 μm) anodes with an N/P ratio ∼ 0.6 were also demonstrated in Li|LiFePO4 cells, which examined the stabilization of Li by LM-P NPs and monitored practical loadings of Li anodes that are close to anode-free systems.

Ultra-robust, high-adhesive, self-healing, and photothermal zwitterionic hydrogels for multi-sensory applications and solar-driven evaporation

“…24 However, it remains challenging to fabricate an LM-filled hydrogel with satisfactory mechanical performance due to the interfacial incompatibility between LMNPs and the hydrogel matrix, which leads to severe macrophase separation and thus poor mechanical properties. 25 Surface modification has recently been exploited to address the above issues by decorating graphene, 26 silica, 27 and a synthetic polymer 28 onto the surface of LMNPs to prevent coalescence and improve stability. However, these encapsulated LMNPs suffer from complicated fabrication processes and chemistry, broad size distribution, potential environmental threats from the utilization of non-degradable materials, and a lack of sufficient functional groups to interact with the hydrogel matrix.…”

“…Surface modification has recently been exploited to address the above issues by decorating graphene, 26 silica, 27 and a synthetic polymer 28 onto the surface of LMNPs to prevent coalescence and improve stability. However, these encapsulated LMNPs suffer from complicated fabrication processes and chemistry, broad size distribution, potential environmental threats from the utilization of non-degradable materials, and a lack of sufficient functional groups to interact with the hydrogel matrix.…”

Hybrid Particle Brush Coatings with Tailored Design for Enhanced Dendrite Prevention and Cycle Life in Lithium Metal Batteries

“…In one failure mode, lithium plates in preferential “hot spots” and strips away from other areas, resulting in mossy morphologies known as dendrites that degrade cell performance with partially conductive pathways between electrodes (soft shorts). Researchers are exploring how to mitigate this early onset failure mode by controlling the nucleation and deposition mechanism as well as by mechanically blocking the protrusion and propagation of dendrites. , This is sought to be achieved by the addition of engineered materials that physicochemically stabilize the lithium metal anode.…”

“…Researchers are exploring how to mitigate this early onset failure mode by controlling the nucleation and deposition mechanism as well as by mechanically blocking the protrusion and propagation of dendrites. 2,3 This is sought to be achieved by the addition of engineered materials that physicochemically stabilize the lithium metal anode.…”

Tailored PVDF Graft Copolymers via ATRP as High-Performance NCM811 Cathode Binders

“…The incorporated CTFE (10 wt %) provides C–Cl sites with lower bond dissociation energy than C–F in PVDF, which facilitates the initiation of grafted polymer chains . Atom transfer radical polymerization (ATRP), the controlled radical polymerization technique, was used to obtain well-controlled grafted chains with low dispersity and desired length and architecture. − We used a light-mediated ATRP with Eosin Y as a photocatalyst for its excellent oxygen-tolerance, temporal control, fast polymerization, as well as greatly reduced copper catalyst loadings . A random copolymer of oligo­(ethylene glycol) methyl ether acrylate and tert -butyl acrylate (PEGA- co -P t BA) was first grafted from the PVDF-CTFE backbone; then, after hydrolysis of P t BA to poly­(acrylic acid) (PAA), the targeted PVDF-CTFE- g -PEGA- co -PAA graft copolymers were obtained (Figure a).…”