Lithiophilic Interphase Porous Buffer Layer toward Uniform Nucleation in Lithium Metal Anodes

ACS Appl. Mater. Interfaces

et al. 2022

The long-term operation of a Li-metal anode remains a great challenge due to the severe dendrite growth in an organic liquid electrolyte. To protect a Li-anode surface from continuous corrosion by an electrolyte, a consistent and robust solid electrolyte interface (SEI) is an essential prerequisite. This work proposes a secure gel polymer electrolyte, which is in situ constructed via a facile polymerization process of vinylidene carbonate inside Li-metal batteries. The liquid components that are not involved in polymerization are well entrapped in the poly(vinyl carbonate) framework, leading to a high oxidative stability of up to 4.5 V (vs Li/Li + ). A Li 3 N−LiFreinforced SEI resulting from the reduction of fluoroethylene carbonate and lithium nitrate additives has a synergistic effect on the suppression of Lidendrite growth. The densely packed Li deposition behavior is revealed by in situ/ex situ microscopic observations. Steady cycling of over 2500 h with a relatively low voltage hysteresis is achieved by the Li||Li symmetric cells. A Coulombic efficiency above 96% upon long-term cycling is available for the asymmetric Li||Cu cells. The smooth operation of batteries with commercial LiFePO 4 cathodes further indicates that the SEI with homogeneity in composition and structure prompts Li deposition with alleviative dendrites.

Section: Resultsmentioning

confidence: 99%

Section: Electrochemical Characteristics Of Gpementioning

confidence: 99%

Synergy of an In Situ-Polymerized Electrolyte and a Li₃N–LiF-Reinforced Interface Enables Long-Term Operation of Li-Metal Batteries

Zhang

Gao

ACS Appl. Mater. Interfaces

et al. 2022

“…Among the other modification perspectives, the 3D matrix can be regarded as an outstanding means of breaking the limitation of the Li surface reaction. During the deposition process, the vast majority of the 3D matrix is immersed and exposed to the electrolyte, which contributes to the dispersion of current density, supply of abundant nucleation sites, and realization of the uniform charge transfer reaction . However, during the dissolution process, things are going to change.…”

Section: Introductionmentioning

confidence: 99%

“…During the deposition process, the vast majority of the 3D matrix is immersed and exposed to the electrolyte, which contributes to the dispersion of current density, supply of abundant nucleation sites, and realization of the uniform charge transfer reaction. 20 However, during the dissolution process, things are going to change. Current 3D skeletons tend to be loaded with high storage Li to ensure a higher energy density.…”

Section: Introductionmentioning

confidence: 99%

Realizing Holistic Charging–Discharging for Dendrite-Free Lithium Metal Anodes via Constructing Three-Dimensional Li⁺ Conductive Networks

Cao

Cheng

ACS Appl. Mater. Interfaces

et al. 2023

Lithium (Li) metal is a promising candidate for next-generation anode materials with high energy densities. However, Li dissolution/deposition processes are limited at the upper surface in contact with the electrolyte, which brings a locally high current density and then results in dendritic Li growth. This restraint of the local surface reaction during cycling has not been solved by commonly used modification strategies. In this study, a three-dimensional (3D) Li + conductive skeleton is activated from atomic layer deposition (ALD) coating Li 3 PO 4 (LPO) on the surface of the Ni foam (LPNF). Then, the skeleton is efficiently constructed in the Li metal anode by the lower-temperature Li infusion. Ionic conductor LPO layers and electronic conductor Ni fibers supply charge transport channels between the electrolyte and the internal Li. The mixed conductive network realizes holistic charge transfer, which is proved by in situ scanning electron microscopy experiments. In virtue of dispersive dissolution/deposition and optimized electrochemical kinetics brought by a Li + conductive network, the composited Li electrode presents an excellent symmetric battery cycling stability (over 1200 h) and enhanced rate performances (stable cycling even at 10.0 mA cm −2 ). When matching with a LiCoO 2 (LCO) cathode, LCO||Li@LPNF full batteries exhibit a capacity retention of 80.8% over 250 cycles. During cycling, there was no evidence of dendrite growth and the remaining Li in the composited anode showed a smooth, compact, and well-combined condition with LPNF. Through constructing a 3D Li + conductive network, the composited Li metal anode breaks through the limit of the local surface reaction; this work proposes a novel insight of realizing holistic charging/discharging for the dendrite-free Li metal anode.

“…With the rapid development of cutting-edge electronic technology and large-scale intelligent machines, high-energy-density storage systems with superior security are urgently required. − Lithium metal anodes, as the most ideal candidate, possess great advantages of high specific capacity (3860 mAh g –1 ) and low reduction potential (−3.04 V vs the standard hydrogen electrode). − However, the commercialization of lithium metal anodes is still impeded by disordered dendrite growth and infinite volume variation during the repeated Li plating/stripping process, thus leading to the inevitable capacity loss, decreased Coulombic efficiency (CE), and short cycle life. − …”

Section: Introductionmentioning

confidence: 99%

Constructing Three-Dimensional Flexible Lithiophilic Scaffolds with Bi₂O₃ Nanosheets toward Stable Li Metal Anodes

ACS Appl. Energy Mater.

Zhong

et al. 2022

The practical application of lithium metal batteries (LMBs) is obstructed by the uncontrollable dendrite growth and large volume change. Herein, we construct a flexible carbon cloth modified with Bi2O3 nanosheets (Bi2O3/CC) as a three-dimensional (3D) lithiophilic skeleton to regulate uniform Li nucleation and deposition. Benefiting from the initial lithiation, dense lithiophilic Li3Bi layers with lithium conductor Li2O (Li3Bi/Li2O) are in-situ-formed through conversion and alloying reactions, which can promote adsorption ability of lithium and improve the speed of Li+ transport according to DFT calculations, thus boosting homogeneous Li plating/stripping behavior. Meanwhile, the conductive 3D structure effectively suppresses Li dendrite formation by reducing the local current density and eliminates volume change. Consequently, the Bi2O3/CC facilitates a high Coulombic efficiency and dendrite-free morphology, near-zero volume change, and superior cyclic stability over 2400 h at 1 mA cm–2 with an ultralow overpotential of 11 mV. Notably, there is no obvious dendritic morphology in Bi2O3/CC even under an ultrahigh areal capacity of 20 mAh cm–2. Moreover, the Li@Bi2O3/CC-LiFePO4 full cell also achieves outstanding cycling performance and rate capability, shedding light on the facile design of the 3D lithiophilic host for advanced lithium-metal anodes.