Suppressing void formation in all-solid-state batteries: the role of interfacial adhesion on alkali metal vacancy transport

Abstract

All-solid-state batteries containing a solid electrolyte and a lithium (Li) or sodium (Na) metal anode are a promising solution to simultaneously increase the energy density and safety of rechargeable batteries....

The Resistive Nature of Decomposing Interfaces of Solid Electrolytes with Alkali Metal Electrodes

“…[53] Yang et al demonstrated that for common Li-metal||SE interfaces, a W adhesion ¿ 0.7 J m −2 was required to prevent the formation of interfacial voids with the application of external pressure of 20-30 MPa. [29] Recently, Seymour and Aguadero [28] have developed a "bond breaking" approach and derived that if W adhesion > 2γ (where γ is the surface energy of Li or Na-metal), the formation of interfacial voids with potential loss of contact during the Li (or Na) stripping could be avoided. Our data suggest that among Li-based interfaces (Table S4), only the Li(100)||Li 2 O(110), Li(100)||Li 3 N(110) and Li(110)||Li 3 N(110) interfaces satisfy this criterion.…”

“…Other studies have investigated the effects of stability of heterogeneous interfaces on the Li-ion transport properties. [27][28][29] Yang and Qi [27] have proposed that an interface with good adhesion, i.e. "lithiophilic interface" can result in a faster critical stripping current density, which is crucial to prevent dendrite growth.…”

“…"lithiophilic interface" can result in a faster critical stripping current density, which is crucial to prevent dendrite growth. Recently, Seymour and Aguadero [28] have shown that Li (or Na)-ion transport across alkali-metal||SE interfaces correlates directly with the interfacial adhesion. Yang et al [29] have employed classical molecular dynamics (MD) to study the process of Li plating and stripping on solid Li 2 O, showing that a coherent interface with strong interfacial adhesion and fast Li-ion diffusion can prevent pore formation at the interface.…”

High critical currents for dendrite penetration and voiding in potassium metal anode solid-state batteries

“…Similarly, the critical current for voiding also depends on the mechanical properties of the metal anode [16,17,41,42]. Voiding occurs when the flux of ions away from the interface current load exceeds the transport of metal atoms to the interface [13,43,44].…”

“…Cycling was carried out at 20 °C under a 2.5 MPa stack-pressure, moving 0.5 mA•h/cm 2 capacity each half cycle, beginning by plating the working electrode (and stripping the counter electrode). Cell polarisation when stripping at 3 mA/cm 2 indicates voiding at the K/K-beta"alumina interface depends on the adhesion of the metal anode to the solid electrolyte [42], and dendrite growth depends not only on the properties of the metal anode but also on the properties of the SE [33][34][35].…”