Flexible and stable high-energy lithium-sulfur full batteries with only 100% oversized lithium

Jian Chang,Yabing Qi,Guoqiang Liu,Zijian Zheng,Zhijun Ma,Yongming Sun,Yi Cui,Dongdong Chen,Dongrui Wang,Qiyao Huang,Jian Shang,Luis K Ono

doi:10.1038/s41467-018-06879-7

Abstract

Lightweight and flexible energy storage devices are urgently needed to persistently power wearable devices, and lithium-sulfur batteries are promising technologies due to their low mass densities and high theoretical capacities. Here we report a flexible and high-energy lithium-sulfur full battery device with only 100% oversized lithium, enabled by rationally designed copper-coated and nickel-coated carbon fabrics as excellent hosts for lithium and sulfur, respectively. These metallic carbon fabrics endow mechanical flexibility, reduce local current density of the electrodes, and, more importantly, significantly stabilize the electrode materials to reach remarkable Coulombic efficiency of >99.89% for a lithium anode and >99.82% for a sulfur cathode over 400 half-cell charge-discharge cycles. Consequently, the assembled lithium-sulfur full battery provides high areal capacity (3 mA h cm−2), high cell energy density (288 W h kg−1 and 360 W h L−1), excellent cycling stability (260 cycles), and remarkable bending stability at a small radius of curvature (<1 mm).

Highlights

Lightweight and flexible energy storage devices are urgently needed to persistently power wearable devices, and lithium-sulfur batteries are promising technologies due to their low mass densities and high theoretical capacities
Both Ni-deposited carbon fabric (NiCF) and Cu-deposited carbon fabric (CuCF) show exceedingly low sheet resistance of 0.48 and 0.1 Ω cm−2, respectively, which are one order of magnitude lower than that of pristine carbon fabrics (CFs) (3.04 Ω cm−2, Fig. 1d), and the resistance remains unchanged over 5000 bending cycles
These metallic fabrics exhibit much higher tensile and compression strength than that of CFs without obvious density increase (Fig. 1d, Supplementary Fig. 3a, and 3b), which is in accordance with the wear-resistant and lightweight requirements for wearable devices

Summary

Introduction

Lightweight and flexible energy storage devices are urgently needed to persistently power wearable devices, and lithium-sulfur batteries are promising technologies due to their low mass densities and high theoretical capacities. We report a flexible and high-energy lithium-sulfur full battery device with only 100% oversized lithium, enabled by rationally designed copper-coated and nickel-coated carbon fabrics as excellent hosts for lithium and sulfur, respectively. These metallic carbon fabrics endow mechanical flexibility, reduce local current density of the electrodes, and, more importantly, significantly stabilize the electrode materials to reach remarkable Coulombic efficiency of >99.89% for a lithium anode and >99.82% for a sulfur cathode over 400 half-cell charge-discharge cycles. The Cu coating renders uniform deposition of Li nanosheets instead of dendrites and leads to an average

Methods

Results

Conclusion