High-energy and durable lithium metal batteries using garnet-type solid electrolytes with tailored lithium-metal compatibility

Abstract

Lithium metal batteries using solid electrolytes are considered to be the next-generation lithium batteries due to their enhanced energy density and safety. However, interfacial instabilities between Li-metal and solid electrolytes limit their implementation in practical batteries. Herein, Li-metal batteries using tailored garnet-type Li7-xLa3-aZr2-bO12 (LLZO) solid electrolytes is reported, which shows remarkable stability and energy density, meeting the lifespan requirements of commercial applications. We demonstrate that the compatibility between LLZO and lithium metal is crucial for long-term stability, which is accomplished by bulk dopant regulating and dopant-specific interfacial treatment using protonation/etching. An all-solid-state with 5 mAh cm−2 cathode delivers a cumulative capacity of over 4000 mAh cm−2 at 3 mA cm−2, which to the best of our knowledge, is the highest cycling parameter reported for Li-metal batteries with LLZOs. These findings are expected to promote the development of solid-state Li-metal batteries by highlighting the efficacy of the coupled bulk and interface doping of solid electrolytes.

Effect of Nb and Ta Simultaneous Substitution on Self-Consolidation Sintering of Li7La3Zr2O12

“…We think that the addition of Al may enhance the stability of Nb-doped LLZO, which is consistent with the results of reported works. 42,43 From these results, it is reasonable to infer that Al, B, Ca, and other additives may be conducive to the stability of LLZO. In general, although the Li + -ion conductivity in this work is slightly lower than that reported for LLZO synthesized through the conventional pressing methods, the presence of Al-containing compounds is conducive to facilitating the selfconsolidation and contributes to the stability of LLZO.…”

“…In some reported works, − the researchers pointed out that Nb-doped LLZO is not stable against Li metal with discoloration because Nb acts as a redox center. The discoloration on the surfaces of Nb50Ta00 and Nb00Ta50 pellets is not observed after contact with Li metal for 12 months in this work.…”

Recent progresses and challenges in aqueous lithium–air batteries relating to the solid electrolyte separator: A mini-review

“…The previous results demonstrate that LATP, LLTO, and LLZO could be suitable for aqueous Li–air batteries, but the gradually deteriorated ionic conductivity and its instability during storage in the air need further concern in the following research. Very recently, we noticed that multiple strategies, such as doping ( Abrha et al, 2020 ; Kobi et al, 2020 ), coating ( Yang et al, 2020 ; Jia et al, 2021 ), and ion exchange ( Kim et al, 2022 ), were proven to be efficient in enhancing solid electrolytes toward air. Also, these may shed light on improving solid electrolyte stability in aqueous Li–air batteries.…”

The interfacial engineering of metal electrodes for high-specific-energy and long-lifespan batteries

“…For solid-state batteries, the stable electrochemical operation has been greatly hindered by the interfacial incompatibility and instability at the solid-state-electrolytes/metal electrodes interface. Firstly, the lattice mismatch between the electrode and SSEs will result in a huge contact loss and limit the discharge performance of the solid-state battery [20,21] . Besides, high reactive metal electrodes can reduce the SSEs to form interphase and the electron-conductive interphase, in turn, this process will promote the constant decomposition of SSEs [22] .…”