A Stretchable Ionic Conductive Elastomer for High‐Areal‐Capacity Lithium‐Metal Batteries

Abstract

Developing high‐areal‐capacity and dendrite‐free lithium (Li) anodes is of significant importance for the practical applications of the Li‐metal secondary batteries. Herein, an effective strategy to stabilize the high‐areal‐capacity Li electrodeposition by modifying the Li metal with a stretchable ionic conductive elastomer (ICE) is demonstrated. The ICE layer prepared via an instant photocuring process shows a promising Li+‐ion conductivity at room temperature. When being used in Li‐metal batteries, the thin ICE coating (~0.27 μm) acts as both a stretchable constraint to minimize the Li loss and a protective layer to facilitate the uniform flux of Li ions. With this ICE‐modifying strategy, the reversibility and cyclability of the Li anodes under high‐areal‐capacity condition in carbonate electrolyte are significantly improved, leading to a stable Li stripping/plating for 500 h at an ultrahigh areal capacity of 20 mAh cm−2 in commercial carbonate electrolyte. When coupled with industry‐level thick LiFePO4 electrodes (20.0 mg cm−2), the cells with ICE‐Li anodes show significantly enhanced rate and cycling capability.

A Waterproof Ion‐Conducting Fluorinated Elastomer with 6000% Stretchability, Superior Ionic Conductivity, and Harsh Environment Tolerance

“…The ICFE‐1.5M could still maintain a stable ionic conductivity after being immersed in water for 72 h (Figure S9, Supporting Information). In striking contrast to the liquid‐free ion‐conducting elastomers in literature (Table S4, Supporting Information), [ 14b‐d,26 ] the ICFE could achieve relatively high ionic conductivities with the same LiTFSI concentration. Intriguingly, it is easy to further enhance the ionic conductivity of the ICFE by increasing the OEGA contents.…”

Mechanism understanding for stripping electrochemistry of Li metal anode

“…Optical microscopy, [146][147][148] transmission electron microscopy, [149][150][151] atomic force microscope, 152 scanning electron microscope, [153][154][155] and transmission X-ray Microscopy 156 have been widely used in characterizing the morphological features of dead Li within a mixture of Li-containing compounds qualitatively. Furthermore, X-ray photoelectron spectroscopy, 157,158 cryogenic transmission electron microscopy, 159,160 scanning electron microscope 161 (with a controlled X-ray beam irradiation intensity), and operando electron paramagnetic resonances pectroscopy 162 were reported to distinguish between Li species in the SEI and dead Li.…”

A Highly Durable Rubber‐Derived Lithium‐Conducting Elastomer for Lithium Metal Batteries

“…Elastomers are an ideal choice for solid electrolytes in long‐life batteries due to their high resilience to accommodate repeated volume changes of advanced electrodes during operation. [ 12 ] In the case of lithium metal batteries, elastomers can afford stable contact with electrodes even when metallic lithium anodes suffer from relatively infinite volume changes during deep charge/discharge cycling. Moreover, elastomers can be assembled with stretchable electrodes to form multifunctional batteries, thus powering wearable electronic devices such as healthcare devices, stretchable sensors, and implantable devices.…”