Electrolyte

Dendrite Growth In Argyrodite Solid Electrolytes

Electrolyte

Dendrite Growth In Argyrodite Solid Electrolytes

Dendrite initiation and propagation are separate processes in Li metal/SE solid-state batteries Li dendrite formation poses a significant risk, leading to short circuits and cell failure during charging at practical rates. Research conducted by the University of Oxford has shed light on this issue, demonstrating that dendrite initiation and growth are distinct processes influenced by different factors. For Li6PS5Cl solid electrolytes, the occurrence of dendrites is largely influenced by local conditions such as the fracture strength at grain boundaries, pore size and density, and current density. Dendrite growth is driven by broader factors, including the material's overall fracture toughness, the physical characteristics of the dendrite, and operational parameters such as current density, stack pressure, and charge capacity utilized per cycle. Experimental observations revealed that battery systems with these electrolytes exhibit varying lifespans based on pressure conditions, with significantly longer life at lower pressures (around 0.1 MPa) compared to moderate pressures (around 7 MPa).

Low pressures can help to suppress dendrite propagation in argyrodite during charging, but might not be beneficial during discharging. Controlling the dynamics of lithium-metal charging and discharging remains a grand challenge.

Academia | P. 225 Source: Ning, Li, Melvin, Chen, Bu, Spencer-Jolly, Liu, Hu, Gao, Perera, Gong, Pu, Zhang, Liu, Hartley, Bodey, Todd, Grant, Armstrong, Marrow, Monroe, Bruce

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