image: Scientists from Beijing Institute of Technology summarized the Li metal anode protection strategies in Li–S batteries. view more
Credit: [Jia-Qi Huang, Beijing Institute of Technology]
They published their work on Jan. 10 in Energy Material Advances.
“Energy storage technologies represented by rechargeable batteries are regarded as an indispensable part of the modern energy system based on renewable yet intermittent energy sources,” said the paper author Jia-Qi Huang, professor of Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology. “Advanced battery systems with high energy density are of great importance to fill the blank for future applications.”
Huang and his research team have focused on Li–S battery, which has a high theoretical energy density of 2600 Wh kg−1 and is widely considered as one of the most promising next-generation battery technologies.
“Li–S batteries employ elemental sulfur as the cathode active material, Li metal as the anode, and ether-based electrolyte for ion transportation and conversion of the sulfur species,” Huang said. “Nowadays, the electrochemical performances of the sulfur cathode have achieved great promotion. High discharge specific capacity and stable cycling of the sulfur cathode can be achieved under high-loading conditions.”
However, the practical application of Li–S batteries are hindered by the poor cycling stability. According to Huang, Li metal is the bottleneck that limits the cycling lifespan of practical Li–S batteries. Under practical working conditions, high-areal-capacity sulfur cathode and limited anode excess aggravate uneven Li stripping and plating to produce massive Li dendrites and inactive Li that render rapid failure of Li metal anode. Moreover, the soluble high-order lithium polysulfides generated from the cathode side diffuse to the Li anode side and chemically react with Li metal, leading to the reduction of Coulombic efficiency, severe Li metal corrosion, and the depletion of active Li as well as exacerbation of the Li anode unevenness.
To construct long cycling practical Li–S batteries, the protection of Li metal anode is the main focus. Rapidly growing attention has been paid to the protection of Li metal anode in working Li–S batteries with essential improvement in battery performances in the recent years. Considering the importance and the great progress of this field, a timely review to summarize the current understandings. Recent advances of Li metal anode protection in Li–S batteries was presented by Huang and his research team.
“From the perspective of the challenges faced by Li metal anode in Li–S batteries, we proposed three protection strategies in general.” Huang said. “The first strategy is guiding uniform Li plating/stripping, the second strategy is reducing polysulfide concentration in anolyte, and the third strategy is reducing polysulfide reaction activity with Li metal anodes.”
To guide uniform Li metal anode plating/stripping, three strategies were introduced regarding constructing composite Li metal anode, introducing robust artificial solid electrolyte interphase, and introducing electrolyte additives. To reduce polysulfide concentration in anolyte, two main strategies were introduced regrading suppressing the diffusion of lithium polysulfides out of the catholyte and reducing the solubility of lithium polysulfides in electrolyte. To reduce polysulfide reaction activity with Li metal anodes, two strategies were introduced through lithium polysulfide encapsulating and reducing the self-activity of Li metal by Li-based alloy or constructing a shielding interphase.
“Although the stability of Li metal anode in Li–S batteries has been significantly improved, there is still a long way to go before practical battery application,” Huang said. “Focusing on the main challenges and the current protecting strategies, it is believed that essential progress will be made in this research frontier and practical application of advanced Li–S batteries will be realized in the near future.”
To inspire future research and development of constructing advanced Li metal anode for Li–S batteries, Huang and his research team also pointed out that the currently proposed protection strategies should be tested in practical Li–S batteries under working conditions, the Li metal anode/electrolyte interfacial behaviors are needed to be further understood, and the balance of both the sulfur cathode and the Li metal anode performances is necessarily to be considered.
Huang is also affiliated with the School of Materials Science and Engineering, Beijing Institute of Technology. Other contributors include Dr. Bo-Quan Li, Chen-Xi Bi, Meng Zhao, and Dr. Xue-Qiang Zhang, Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology; Li-Peng Hou, Zheng Li, and Prof. Qiang Zhang, Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University.
The following authors have additional affiliations: Dr. Bo-Quan Li, Chen-Xi Bi, Meng Zhao, and Dr. Xue-Qiang Zhang, School of Materials Science and Engineering, Beijing Institute of Technology.
Beijing Natural Science Foundation (JQ20004), the National Key Research and Development Program (2021YFB2400300), the National Natural Science Foundation of China (22109007 and 22209010), Beijing Institute of Technology Research Fund Program for Young Scholars, and the Tsinghua University Initiative Scientific Research Program supported this work.
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Reference
Authors: CHEN-XI BI, LI-PENG HOU, ZHENG LI, MENG ZHAO, XUE-QIANG ZHANG, BO-QUAN LI , QIANG ZHANG, AND JIA-QI HUANG
Title of original paper: Protecting lithium metal anodes in lithium–sulfur batteries: A review
Journal: Energy Material Advances
DOI: 10.34133/energymatadv.0010
Affiliations:
1School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
2Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China.
3Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
About the Authors:
Dr. Jia-Qi Huang received his Bachelor's and Ph.D. degree in chemical engineering from Tsinghua University in 2007 and 2012, respectively. He is currently a full professor in Advanced Research Institute for Multidisciplinary Science at Beijing Institute of Technology. His research focuses on interface electrochemistry and advanced energy materials design in high-energy-density rechargeable batteries, especially for lithium–sulfur batteries and lithium metal anode.
Dr. Bo-Quan Li obtained his bachelor degree from Department of Chemistry, Tsinghua University and PhD degree from Department of Chemical Engineering, Tsinghua University. He is currently an associate research fellow in Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology. His research interests are advanced energy materials for lithium–sulfur batteries, lithium metal anodes, and bifunctional oxygen electrocatalysis in zinc–air batteries.
Journal
Energy Material Advances
COI Statement
The authors declare that they have no competing interests.