High Volumetric Energy Density Sulfur Cathode with Heavy and Catalytic Metal Oxide Host for Lithium-Sulfur Battery.

Ya‐Tao Liu,Guo‐Ran Li,Sheng Liu,Tian‐Ying Yan,Xue‐Ping Gao

doi:10.1002/advs.201903693

Ya‐Tao Liu, Guo‐Ran Li + Show 3 more

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https://doi.org/10.1002/advs.201903693

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Abstract

For high‐energy lithium–sulfur batteries, the poor volumetric energy density is a bottleneck as compared with lithium–ion batteries, due to the low density of both the sulfur active material and sulfur host. Herein, in order to enhance the volumetric energy density of sulfur cathode, a universal approach is proposed to fabricate a compact sulfur cathode with dense materials as sulfur host, instead of the old‐fashioned lightweight carbon nanomaterials. Based on this strategy, heavy lanthanum strontium manganese oxide (La0.8Sr0.2MnO3), with a high theoretical density of up to 6.5 g cm−3, is introduced as sulfur host. Meanwhile, the La0.8Sr0.2MnO3 host also acts as an efficient electrocatalyst to accelerate the diffusion, adsorption, and redox dynamics of lithium polysulfides in the charge–discharge processes. As a result, such S/La0.8Sr0.2MnO3 cathode presents high gravimetric/volumetric capacity and outstanding cycling stability. Moreover, an ultra‐high volumetric energy density of 2727 Wh L−1 ‐cathode is achieved based on the densification effect with higher density (1.69 g cm−3), which is competitive to the Ni‐rich oxide cathode (1800–2160 Wh L−1) of lithium–ion batteries. The current study opens up a path for constructing high volumetric capacity sulfur cathode with heavy and catalytic host toward practical applications of lithium–sulfur batteries.

Highlights

For high-energy lithium–sulfur batteries, the poor volumetric energy density is battery has achieved a high gravimetric energy density of 350–609 Wh kg−1 in the past a bottleneck as compared with lithium–ion batteries, due to the low density of few years,[3] showing a favorable application both the sulfur active material and sulfur host
The inferior volumetric endensity of 2727 Wh L−1-cathode is achieved based on the densification effect with higher density (1.69 g cm−3), which is competitive to the Ni-rich oxide cathode (1800–2160 Wh L−1) of lithium–ion batteries
The current study opens up a path for constructing high volumetric capacity sulfur cathode with heavy and catalytic host toward practical applications of lithium–sulfur batteries

Summary

Introduction

For high-energy lithium–sulfur batteries, the poor volumetric energy density is battery has achieved a high gravimetric energy density of 350–609 Wh kg−1 in the past a bottleneck as compared with lithium–ion batteries, due to the low density of few years,[3] showing a favorable application both the sulfur active material and sulfur host. A three “high” principle is proposed in this study to fabricate compact Scathode for achieving high volumetric energy density (Figure 1): (1) “high” sulfur content of above 80 wt% for the sulfur-based composite, (2) “high” sulfur loading of above 4 mg cm−2 for thick sulfur cathode, and (3) “high” density for the host materials (heavy host) with good electrocatalytic activity.

Results

Conclusion