Dendrites in Solid‐State Batteries: Ion Transport Behavior, Advanced Characterization, and Interface Regulation

Abstract

Solid‐state electrolytes (SSEs) are attracting growing interest for next‐generation Li‐metal batteries with theoretically high energy density, but they currently suffer from safety concerns caused by dendrite growth, hindering their commercial applications. Interfaces between SSEs and solid lithium are argued to be crucial, affecting dendrite growth and determining solid‐state batteries (SSBs) performance. The buried and localized nature of the interface poses a huge challenge for direct characterization under working conditions. Recent review articles have been devoted to evaluating the conductivity and chemical stability of SSEs. Recognizing this, in this Review, the focus is on understanding lithium dendrite beyond conventional factors and offering a perspective on various surface/interface and microstructural phenomena that require close attention by both experimentalists and theoreticians. The complicated ion‐transport mechanism and chemomechanical information correlated with interface and lithium dendrite are discussed. Rational solutions are provided to engineer functional interfaces to suppress lithium dendrites and accelerate progress towards the commercialization of SSBs.

A Quasi‐Double‐Layer Solid Electrolyte with Adjustable Interphases Enabling High‐Voltage Solid‐State Batteries

“…The lithium dendrite growth on the anode/electrolyte interface and the electrode expanding and shrinking changes during cycling could deteriorate the intimate electrode-electrolyte interface, resulting in poor electrochemical performance of the batteries. [43,44] Therefore, advanced characterizations in situ ECCS was adopted to investigate structural and chemical stability of the D-PLL-CPEs/hard carbon interface, promoting the mechanism understanding of the interface behavior and shown in Figure 4a. There is hardly volume expansion on hard carbon based on intercalation mechanism.…”

From Lithium‐Metal toward Anode‐Free Solid‐State Batteries: Current Developments, Issues, and Challenges

“…[133] Furthermore, fundamental findings on dendrite growth in solid-state batteries and advanced characterization techniques [134] have recently been reviewed. [128,135] Albertus et al [136] precisely discussed recent advances and prominent obstacles to realize solid-state Li metal batteries, including gaps in material science, processing science and design engineering. Furthermore, recent advances and perspectives on the fabrication of thin SSE and corresponding cell designs were reviewed.…”

Promoting Mechanistic Understanding of Lithium Deposition and Solid‐Electrolyte Interphase (SEI) Formation Using Advanced Characterization and Simulation Methods: Recent Progress, Limitations, and Future Perspectives

“…Dendritic Li in SSBs preferably grows at the defects of the electrode and the solid electrolyte (e.g., cracks, impurities, grain boundaries, and voids). [ 79 ] The underlying mechanisms of Li dendrite formation and growth in SSBs remains poorly understood. Specifically, i) the Li nucleation and dendrite formation could happen at the Li‐solid electrolyte interface, induced by the poor interfacial contact caused by geometric inhomogeneities, such as surface roughness, voids and defects; ii) Li dendrites could also form inside solid electrolytes induced by electrons from their residual electrical conductivity, oxygen framework, and pore surface; iii) grain boundaries inside solid electrolytes could induce Li propagation.…”