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Batteries

Improving Solid Electrolytes for All-Solid-State Batteries

Strategic Insights

— 1 min read

Researchers at Doshisha University have made a significant breakthrough in improving the solid electrolytes used in all-solid-state batteries. The study, published in Electrochemistry, focuses on the garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZT) electrolyte, which has shown promising results due to its high Li-ion conductivity and electrochemical stability against Li metal anodes. However, the presence of pores and voids in the electrolyte has hindered its application. To address this issue, the researchers investigated the effects of Li2WO4 (LWO) and Al2O3 sintering aids on the densification of LLZT.

Key Takeaways:

  • The addition of 4 wt% LWO and 2 wt% Al2O3 resulted in a very high relative density of 99.3%, significantly reducing the amount of pores and voids in the electrolyte.
  • The critical current density (CCD) was improved from 0.2 to 0.4 mA cm-2, indicating enhanced electrochemical stability.
  • Reducing the amount of lanthanum in LLZT led to the formation of lithium zirconate as a self-forming sintering aid, achieving a higher relative density of 99.7% and further improving the CCD to 0.6 mA cm-2.
  • The research demonstrates the potential of using LWO and Al2O3 sintering aids to improve the densification and electrochemical performance of LLZT electrolytes.
  • The study highlights the importance of optimizing the electrolyte composition and structure to achieve high-performance all-solid-state batteries.

Statistics:

  • 99.3% relative density obtained with 4 wt% LWO and 2 wt% Al2O3.
  • 99.7% relative density achieved with La-deficient (6%) LLZT and 4 wt% LWO and 2 wt% Al2O3.
  • CCD improved from 0.2 to 0.4 mA cm-2.
  • CCD further improved to 0.6 mA cm-2 with reduced lanthanum content.

Sources:

  • "Improvement of Short-Circuit Tolerance of Garnet Type Solid Electrolyte Li6.4La3Zr1.4Ta0.6O12 by Li2WO4 and Al2O3 Sintering Aids and La Deficiency." Electrochemistry, 2025,93(6):063022-063022.
  • Electrochemistry publisher: The Electrochemical Society of Japan.
  • https://doi-org.sdpl.idm.oclc.org/10.5796/electrochemistry.25-71040.

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