La(OH)₃-Based Lithium Ionic Conductor for Quasi-Solid-State Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Quasi-solid-state lithium metal batteries (QSSLMBs) offer advanced energy storage potential but are hindered by electrolyte instability, high costs, and poor interfaces.
• Developing stable and efficient electrolytes is crucial for next-generation QSSLMBs.

Purpose of the Study:

• To develop a novel, air-stable, and cost-effective lithium-ion conductor for QSSLMBs.
• To enhance the interfacial compatibility and ionic conductivity of polymer electrolytes.
• To address key challenges in QSSLMB applications.

Main Methods:

• Synthesis of a lanthanum hydroxide-based lithium conductor, Li _0.15Sr _0.525La _0.6(OH) ₃ (LSLOH).
• Incorporation of LSLOH into a polyethylene oxide (PEO)-LiTFSI polymer electrolyte (PL) to form a quasi-solid-state electrolyte (PL-LSLOH).
• Electrochemical characterization of the PL-LSLOH electrolyte and evaluation of LiNi _0.6Co _0.1Mn _0.3O ₂ | PL-LSLOH | Li pouch cells.

Main Results:

• The synthesized LSLOH is air-stable, cost-effective, and exhibits Li ⁺ conductivity of 0.1 mS cm^-1 at 30 °C.
• The PL-LSLOH electrolyte demonstrated improved Li ⁺ transport and induced a protective LiOH and Li ₂O-rich solid electrolyte interphase, suppressing lithium dendrite growth.
• The pouch cells achieved a high capacity of 2.2 mAh cm^-2 at 0.83 mA cm^-2 over 200 cycles with 92.5% capacity retention.

Conclusions:

• La(OH) ₃-based ionic conductors offer a promising solution for developing stable and high-performance QSSLMBs.
• The developed electrolyte design effectively addresses critical barriers in QSSLMB technology, paving the way for potential scale-up.
• This work presents a novel approach to electrolyte engineering for advanced lithium metal batteries.