Solid Thin-Film Battery Using a Densely Packed LiNi_0.5Mn_1.5O₄ Crystal Layer.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• 5 V-class LiNi_0.5Mn_1.5O₄ (LNMO) cathodes offer high energy density potential for solid-state lithium batteries.
• Achieving stable cycling and high performance in these batteries requires optimized electrode structures and interfaces.

Purpose of the Study:

• To investigate the stable cycling performance of solid thin-film lithium batteries utilizing densely packed LNMO crystal layers.
• To evaluate the impact of annealing on the interfacial resistance between LNMO and Li₃PO₄ solid electrolyte.

Main Methods:

• Fabrication of solid thin-film lithium batteries with densely packed LNMO positive electrodes.
• Electrochemical cycling and impedance spectroscopy to assess battery performance and interfacial resistance.
• Post-annealing treatment of the assembled battery.

Main Results:

• Demonstrated stable cycling of a solid thin-film Li battery with a densely packed LNMO layer.
• Annealing reduced the interfacial resistance between Li₃PO₄ solid electrolyte and LNMO by an order of magnitude (from 5.3 × 10² to 5.7 × 10¹ Ωcm²).
• Enhanced battery performance was observed after annealing.

Conclusions:

• Densely packed LNMO layers are promising for high-performance all-solid-state lithium batteries.
• Annealing is an effective method to reduce interfacial resistance and improve battery performance.
• This study provides a foundation for developing advanced solid-state batteries with LNMO cathodes.