Dense Graphene Monolith for High Volumetric Energy Density Li–S Batteries |
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Authors: | Huan Li Ying Tao Chen Zhang Donghai Liu Jiayan Luo Weichao Fan Yue Xu Youzhi Li Conghui You Zheng‐Ze Pan Mingchun Ye Zhengyu Chen Zhang Dong Da‐Wei Wang Feiyu Kang Jun Lu Quan‐Hong Yang |
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Affiliation: | 1. Nanoyang Group, School of Chemical Engineering and Technology, Tianjin University, Tianjin, China;2. Shenzhen Key Laboratory for Graphene‐based Materials, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China;3. School of Chemical Engineering, UNSW Australia (The University of New South Wales), Sydney, NSW, Australia;4. Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL, USA;5. Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China |
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Abstract: | Despite the outstanding gravimetric performance of lithium–sulfur (Li–S) batteries, their practical volumetric energy density is normally lower than that of lithium‐ion batteries, mainly due to the low density of nanostructured sulfur as well as the porous carbon hosts. Here, a novel approach is developed to fabricate high‐density graphene bulk materials with “ink‐bottle‐like” mesopores by phosphoric acid (H3PO4) activation. These pores can effectively confine the polysulfides due to their unique structure with a wide body and narrow neck, which shows only a 0.05% capacity fade per cycle for 500 cycles (75% capacity retention) for accommodating polysulfides. With a density of 1.16 g cm?3, a hybrid cathode containing 54 wt% sulfur delivers a high volumetric capacity of 653 mA h cm?3. As a result, a device‐level volumetric energy density as high as 408 W h L?1 is achieved with a cathode thickness of 100 µm. This is a periodic yet practical advance to improve the volumetric performance of Li–S batteries from a device perspective. This work suggests a design principle for the real use Li–S batteries although there is a long way ahead to bridge the gap between Li–S batteries and Li–ion batteries in volumetric performance. |
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Keywords: | graphene monolith ink‐bottle‐like pores lithium– polysulfide batteries polysulfides volumetric performance |
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