Evaluation of The Electrochemo-Mechanically Induced Stress in All-Solid-State Li-Ion Batteries

Abstract

The mechanical degradation of all-solid-state Li-ion batteries (ASSLBs) is expected to be more severe than that in traditional Li-ion batteries with liquid electrolytes due to the additional mechanical constraints imposed by the solid electrolyte on the deformation of electrodes. Cracks and fractures could occur both inside the solid electrolyte (SE) and at the SE/electrode interfconce. A coupled electrochemical-mechanical model was developed and solved by the Finite Element Method (FEM) to evaluate the stress development in ASSLBs. Two sources of volume change were considered, namely the expansion/shrinkage of electrodes due to lithium concentration change and the interphase formation at the SE/electrode interface due to the decomposition of SEs. The most plausible solid electrolyte decomposition reactions and their associated volume change were predicted by density functional theory (DFT) calculations. It was found that the stress associated with a volume change due to solid electrolyte decomposition can be much more significant than that of electrode volumetric changes associated with Li insertion/extraction. This model can be used to design 3D ASSLB architectures to minimize their internal stress generation.

In Situ Investigation of Chemomechanical Effects in Thiophosphate Solid Electrolytes

“…Stress within individual battery components and/or at interfaces can occur because of physical volume change, 5,33 the formation of gas, 34,35 and/or mass (ion) transport. [36][37][38] While concentration gradients do not exist in a single ion-conducting electrolyte, there is the potential for stress-assisted diffusion at solid|solid interfaces. 38 Irregular interphase growth or Li 0 electrodeposition can lead to stress gradients in a solid electrolyte, and alter the local energy level of the cation and contribute to directed ionic transport.…”

In Situ Formed Ag‐Li Intermetallic Layer for Stable Cycling of All‐Solid‐State Lithium Batteries

“…Furthermore, the small increase in impedance compared to that of the control case during cycling further supports the interfacial stability of the Ag‐Li cell (Figure S13 , Supporting Information). Therefore, we strongly believe that the decent interfacial stability of the ALI to the sulfide‐based SE reduced chemical strain by mitigating parasitic reactions at the SE interface, [ 48 ] thereby alleviating the crack generation and preventing the short‐circuit caused by Li filament growth. Accordingly, owing to these impressive features, including being lithiophilic, being dendrite‐free, and showing improved interfacial stability, the Ag‐Li symmetric cell achieved a lower overpotential and better cycling performance up to 150 cycles compared to the control cell (Figure 3l ).…”

All‐Solid‐State Thin Film μ‐Batteries for Microelectronics

“…Only in recent years, it has been gradually received more attentions. [ 336 , 337 , 338 ] The internal strain in each component of the ASTBs can be caused by at least two parameters, namely change in electrochemical state and temperature. Compared to electrochemical state, thermally induced strain is negligible.…”