Extremely Low Resistance of Li₃PO₄ Electrolyte/Li(Ni_0.5Mn_1.5)O₄ Electrode Interfaces

Abstract

Solid-state Li batteries containing Li(NiMn)O as a 5 V-class positive electrode are expected to revolutionize mobile devices and electric vehicles. However, practical applications of such batteries are hampered by the high resistance at their solid electrolyte/electrode interfaces. Here, we achieved an extremely low electrolyte/electrode interface resistance of 7.6 Ω cm in solid-state Li batteries with Li(NiMn)O. Furthermore, we observed spontaneous migration of Li ions from the solid electrolyte to the positive electrode after the formation of the electrolyte/electrode interface. Finally, we demonstrated stable fast charging and discharging of the solid-state Li batteries at a current density of 14 mA/cm. These results provide a solid foundation to understand and fabricate low-resistance electrolyte/electrode interfaces.

Physical Vapor Deposition in Solid‐State Battery Development: From Materials to Devices

“…The significant differences in the reported spinel‐LiPON interface resistances could also be attributed to a possible deterioration of the interface during LiPON sputtering as it was reported for LCO thin films. This hypothesis is supported by the low interface resistances that were reported for LNMO/Li 3 PO 4 deposited by PLD, namely 7.6 Ω cm 2 for (100) LNMO [ 205 ] and 34 Ω cm 2 for (111) LNMO. [ 206 ]…”

Room temperature synthesis and phase transformation of lithium phosphate Li3PO4as solid electrolyte

“…Lithium phosphate Li 3 PO 4 is one of the attractive solid electrolyte materials due to its wide electrochemical potential, strong glass-forming capability, and simple composition for the next generation all-solid-state lithium battery (LIB) applications [1][2][3][4]. Especially, an amorphous form of Li 3 PO 4 exhibits low electrode/solid electrolyte interfacial resistance in use as solid electrolyte for all-solid-state thin-film LIB [5][6][7].…”

Microscopic ion migration in solid electrolytes revealed by terahertz time-domain spectroscopy

“…The temperature dependence of the THz conductivity revealed the intrinsic migration energy of the vacancy. This method is applicable to various solid electrolytes in protonic ceramic fuel cells (PCFC) 53–57 and all-solid-state lithium ion batteries 10,58 , because the attempt frequencies of the ion transport in these materials are also expected to lie around several THz 59 . Since THz-TDS should reveal the hidden mechanism of ionic conduction, our proposed method is useful for development of novel solid electrolytes for fuel cells or all-solid-state batteries.…”