Enabling \u201clithium-free\u201d manufacturing of pure lithium metal solid-state batteries through in situ plating

Michael J Wang,Jeff Sakamoto,Eric Carmona,Arushi Gupta,Paul Albertus

doi:10.1038/s41467-020-19004-4

Michael J Wang, Jeff Sakamoto + Show 3 more

Open Access

https://doi.org/10.1038/s41467-020-19004-4

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Abstract

The coupling of solid-state electrolytes with a Li-metal anode and state-of-the-art (SOA) cathode materials is a promising path to develop inherently safe batteries with high energy density (>1000 Wh L−1). However, integrating metallic Li with solid-electrolytes using scalable processes is not only challenging, but also adds extraneous volume since SOA cathodes are fully lithiated. Here we show the potential for “Li-free” battery manufacturing using the Li7La3Zr2O12 (LLZO) electrolyte. We demonstrate that Li-metal anodes >20 μm can be electroplated onto a current collector in situ without LLZO degradation and we propose a model to relate electrochemical and nucleation behavior. A full cell consisting of in situ formed Li, LLZO, and NCA is demonstrated, which exhibits stable cycling over 50 cycles with high Coulombic efficiencies. These findings demonstrate the viability of “Li-free” configurations using LLZO which may guide the design and manufacturing of high energy density solid-state batteries.

Highlights

The coupling of solid-state electrolytes with a Li-metal anode and state-of-the-art (SOA) cathode materials is a promising path to develop inherently safe batteries with high energy density (>1000 Wh L−1)
The open circuit voltage (OCV) begins at ∼1.8 V and upon application of a constant current density of 0.05 mA cm−2, the potential quickly drops to 0 V followed by a negative potential, which indicates the onset of sustained electrodeposition of Li
Based on the electrochemical impedance spectroscopy (EIS) analysis shown in Fig. 1c, the total ionic impedance of the cell is ∼350 Ω cm[2], which corresponds to a total DC polarization of ∼17.5 mV at a 0.05 mA cm−2 current density, which is reasonably consistent with the steady-state plating potential

Summary

Introduction

The coupling of solid-state electrolytes with a Li-metal anode and state-of-the-art (SOA) cathode materials is a promising path to develop inherently safe batteries with high energy density (>1000 Wh L−1). We demonstrate that commercially relevant capacities (≥3 mAh cm−2) of Li metal, comparable to current state-of-the-art Li-ion electrodes, can be both plated and stripped from an LLZO/CC interface.

Results

Conclusion