Modulating the electrical conductivity of a graphene oxide-coated 3D f…
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논문명 | Modulating the electrical conductivity of a graphene oxide-coated 3D framework for guiding bottom-up lithium growth |
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저자 | Kwang Hyun Park, Dong Woo Kang, bc Jun-Woo Park, Jeong-Hee Choi, Soon-Jik Hong, Sung Ho Song, Sang-Min Lee, Janghyuk Moon and Byung Gon Kim |
저널명 | Journal of Materials Chemistry A |
게재년월 | 2020/12/10 |
Vol. pp |
Realizing Li-metal batteries requires overcoming several hurdles, such as volume changes, a thickening
solid electrolyte interphase, and safety issues associated with uncontrollable Li growth. Introducing a 3D
conductive framework that improves Li reversibility by decreasing the local current density and
alleviating volume changes can mitigate these issues, but inevitable Li growth on the top surface remains
problematic. To address this, herein, we report an electrical conductivity-controlled 3D host consisting
of a glass fiber (GF) framework, size-/conductivity-controlled partially reduced graphene oxide (PrGO),
and a Cu substrate (PrGO–GF/Cu). Due to the synergistic interplay between the 3D GF alleviating
volume fluctuation and PrGO with desirable conductivity, the PrGO–GF/Cu host mitigates the Li top
plating and guides preferential Li deposition/dissolution at the bottom of the structure. As a result, the
PrGO–GF/Cu exhibits substantially improved electrochemical performance in coulombic efficiency,
symmetric cell, and LiFePO4 full cell tests. Experimental and theoretical studies reveal that modulating
the electrical conductivity of the framework within an optimal range is an easy and effective way of
suppressing Li top plating and facilitating Li bottom plating/stripping. This work demonstrates the
importance of controlling the electrical conductivity to enable reversible behavior of Li in the Li-metal
host anode, and a facile method to fabricate a 3D host that prevents Li top plating