Linking the Defects to the Formation and Growth of Li Dendrite in All‐Solid‐State Batteries

Abstract

The nucleation and growth of Li metal during deposition and the associated dendrite penetration are the critical and fundamental issues influencing the safety and power density of solid‐state lithium metal batteries (SSLBs). However, investigations on Li metal deposition/dissolution especially the formation and growth of Li dendrites and their determining factors in the all‐solid‐state electrochemical systems are still lacking. In this work, in situ observations of the Li metal growth process, and defects induced heterogeneous deposition under cathodic load, are reported. By exploiting in situ scanning electron microscopy, along with electrochemical analytical approaches, the spatial distribution and morphological evolution of the deposited Li at the electrode|solid electrolyte interface are obtained and discussed. This investigation reveals that the formation of lithium whiskers is decided by the local Li ion flux and the deposition active sites, which are closely dependent on the content and types of defects in the polycrystalline electrolyte. Moreover, the defect regions exhibit faster Li deposition kinetics and higher nucleation tendency. These results can advance the fundamental understanding of the Li penetration mechanism in SSLBs.

Research Progress and Perspective on Lithium/Sodium Metal Anodes for Next‐Generation Rechargeable Batteries

“…[116] Furthermore, interface defects can act as penetration sites for dendrite nucleation and growth. [117,118] So, engineering a passage layer to render tight contact between electrode and SSE is needed. Several methods have been investigated to address interfacial resistance: space charge layer (SCL) formation, which includes direct co-sintering of cathode and solid electrolyte, or in-situ synthesis of solid electrolyte and cathode.…”

Clarifying the Electro‐Chemo‐Mechanical Coupling in Li10SnP2S12 based All‐Solid‐State Batteries

“…[39] A recent study from Yang's group clearly demonstrates that these SE defects exhibit faster Li deposition kinetics and high nucleation tendency. [40] Nevertheless, given the scale and extent of the currently discovered reaction hot-spots (Figure 4h) it is suggested that further dedicated studies on ionic conduction path, [41] electron conduction, [14] and/ or electric field distribution [38] in ASSBs are desirable. [42]…”

Recent advances in dendrite-free lithium metal anodes for high-performance batteries

“…The results showed that the Li deposition sites and growth pattern depend strongly on the quality of the electrolyte substrate and are closely related to the defects (pores, grain boundaries, impurity phases) within the electrolyte. 43 Moreover, Sun et al directly observed lithium dendrite formation within the Li 3 PS 4 electrolyte. They attributed the formation of lithium dendrite to P- and S-based crystalline defects in the solid-state-electrolyte, which was verified by the use of cryo-transmission electron microscopy morphologies and theoretical calculations.…”