An efficient gel polymer electrolyte for dendrite-free and long cycle life lithium metal batteries

ACS Appl. Mater. Interfaces

Gao

Wang

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: Introductionmentioning

confidence: 99%

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

ACS Appl. Mater. Interfaces

Gao

Wang

et al. 2022

“…200) and (101) (001), the (110) face of lithium metal and the polymer phase in the amorphous region were found in the interface. In addition, a PEO-based gel polymer electrolyte (PEO-GPE) was prepared by Reza et al [46] whose interface with lithium metal anode was explored by TEM. As shown in Figure 8f, TEM showed that GPE [47] can form SEI layers with a mosaic structure on lithium metal anode, which consisted of many inorganic nanocrystals and an amorphous organic/polymer phase.…”

Section: Transmission Electron Microscopymentioning

confidence: 99%

Multi‐Scale Characterization Techniques for Polymer‐Based Solid‐State Lithium Batteries

Macro Chemistry & Physics

Zhou

et al. 2022

The interface compatibility and ionic conductivity of polymer electrolytes play crucial roles in electrochemical behaviors of polymer-based solid-state batteries. Advanced characterization techniques are essential to explore interface compatibility and ion transport mechanisms. In this review, the recent application of multi-scale characterization techniques in polymer-based solid-state lithium batteries (PSSLBs) is summarized, in terms of microscopy techniques, X-ray techniques, spectroscopy techniques, and neutron techniques. These characterization technologies span the atomic scale, micro scale, mesoscale, and macroscopic scale. In particular, the in situ characterization with high time resolution is highlighted in each of the techniques, in order to promote the exploration of dynamic interface evolution in operating batteries. It is hoped that this review will contribute to the development of multi-scale in situ characterization techniques, thus promoting the improvement of energy density for PSSLBs.

“…With the rapid growth of energy demand, it becomes urgent to develop new Li-ion batteries to increase their specific energy. − However, the commercial Li-ion batteries with liquid electrolytes have serious safety problems, potentially leading to safety concerns such as electrolyte leakage, thermal runaway, and even fire explosion accidents. − To solve these problems, it is of great importance to explore new solid-state electrolytes (SSEs) for solid-state lithium batteries with high safety and energy density . Generally, the SSEs can be divided into various types, such as polymer electrolytes, oxide electrolytes, and sulfide electrolytes. − Among the above options, the quasi-solid-state electrolyte of an ion gel has also received broad attention and comprehensive study. − Usually, the ion gel composed of a solid-state gelator and an ionic liquid can retain the high ionic conductivity of the ionic liquid, good mechanical strength, and excellent thermal stability. − …”

Section: Introductionmentioning

confidence: 99%

Rapid Self-Healing Gel Electrolyte Based on Deep Eutectic Solvents for Solid-State Lithium Batteries

ACS Appl. Mater. Interfaces

et al. 2022

A deep eutectic solvent (DES) is a promising electrolyte choice for lithium metal batteries. However, the DES liquid electrolyte causes safety concerns and side reactions with the lithium anode. Therefore, it is necessary to solidify the DES-based electrolyte and enhance its electrochemical stability. Herein, we present a novel DES-based rapid self-healing gel electrolyte, which is able to self-smooth its surface cracks in only 30 min. The electrolyte exhibits noncombustibility (SET = 4 s g–1), high ionic conductivity (1.1 × 10–3 S cm–1 at 25 °C), and a wide electrochemical voltage window (4.5 V vs Li/Li+). As a result, the solid-state lithium batteries coupling the gel electrolyte with the Li anode and LiFePO4 cathode deliver a high specific capacity of 135.4 mA h g–1 with durable cyclic stability (>1200 h). This work provides valuable insights for design of fire-resistant and high-energy solid-state lithium batteries.