Electrical resistance of the current collector controls lithium morphology

Solomon T Oyakhire; Wenbo Zhang; Andrew Shin; Rong Xu; David T Boyle; Zhiao Yu; Yusheng Ye; Yufei Yang; James A Raiford; William Huang; Joel R Schneider; Yi Cui; Stacey F Bent

doi:10.1038/s41467-022-31507-w

Electrical resistance of the current collector controls lithium morphology

Nat Commun. 2022 Jul 9;13(1):3986. doi: 10.1038/s41467-022-31507-w.

Authors

Solomon T Oyakhire^#¹, Wenbo Zhang^#², Andrew Shin², Rong Xu², David T Boyle³, Zhiao Yu³, Yusheng Ye², Yufei Yang², James A Raiford¹, William Huang², Joel R Schneider¹, Yi Cui^{4

5}, Stacey F Bent⁶

Affiliations

¹ Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA.
² Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA.
³ Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.
⁴ Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA. yicui@stanford.edu.
⁵ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA. yicui@stanford.edu.
⁶ Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. sbent@stanford.edu.

^# Contributed equally.

Abstract

The electrodeposition of low surface area lithium is critical to successful adoption of lithium metal batteries. Here, we discover the dependence of lithium metal morphology on electrical resistance of substrates, enabling us to design an alternative strategy for controlling lithium morphology and improving electrochemical performance. By modifying the current collector with atomic layer deposited conductive (ZnO, SnO₂) and resistive (Al₂O₃) nanofilms, we show that conductive films promote the formation of high surface area lithium deposits, whereas highly resistive films promote the formation of lithium clusters of low surface area. We reveal an electrodeposition mechanism in which radial diffusion of electroactive species is promoted on resistive substrates, resulting in lateral growth of large (150 µm in diameter) planar lithium deposits. Using resistive substrates, similar lithium morphologies are formed in three distinct classes of electrolytes, resulting in up to ten-fold improvement in battery performance. Ultimately, we report anode-free pouch cells using the Al₂O₃-modified copper that maintain 60 % of their initial discharge capacity after 100 cycles, displaying the benefits of resistive substrates for controlling lithium electrodeposition.