TY - JOUR
T1 - Solid-State Divalent Ion Conduction in ZnPS3
AU - Martinolich, Andrew J.
AU - Lee, Cheng Wei
AU - Lu, I. Te
AU - Bevilacqua, Sarah C.
AU - Preefer, Molleigh B.
AU - Bernardi, Marco
AU - Schleife, André
AU - See, Kimberly A.
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/5/28
Y1 - 2019/5/28
N2 - Next-generation batteries based on divalent working ions have the potential to both reduce the cost of energy storage devices and increase performance. Examples of promising divalent systems include those based on Mg2+, Ca2+, and Zn2+ working ions. Development of such technologies is slow, however, in part due to the difficulty associated with divalent cation conduction in the solid state. Divalent ion conduction is especially challenging in insulating materials that would be useful as solid-state electrolytes or protecting layers on the surfaces of metal anodes. Furthermore, there are no reports of divalent cation conduction in insulating, inorganic materials at reasonable temperatures, prohibiting the development of structure-property relationships. Here, we report Zn2+ conduction in insulating ZnPS3, demonstrating divalent ionic conductivity in an ordered, inorganic lattice near room temperature. Importantly, the activation energy associated with the bulk conductivity is low, 351 ± 99 meV, comparable to some Li+ conductors such as LTTO, although not as low as the superionic Li+ conductors. First-principles calculations suggest that the barrier corresponds to vacancy-mediated diffusion. Assessment of the structural distortions observed along the ion diffusion pathways suggests that an increase in the P-P-S bond angle in the [P2S6]4- moiety accommodates the Zn2+ as it passes through the high-energy intermediate coordination environments. ZnPS3 now represents a baseline material family to begin developing the structure-property relationships that control divalent ion diffusion and conduction in insulating solid-state hosts.
AB - Next-generation batteries based on divalent working ions have the potential to both reduce the cost of energy storage devices and increase performance. Examples of promising divalent systems include those based on Mg2+, Ca2+, and Zn2+ working ions. Development of such technologies is slow, however, in part due to the difficulty associated with divalent cation conduction in the solid state. Divalent ion conduction is especially challenging in insulating materials that would be useful as solid-state electrolytes or protecting layers on the surfaces of metal anodes. Furthermore, there are no reports of divalent cation conduction in insulating, inorganic materials at reasonable temperatures, prohibiting the development of structure-property relationships. Here, we report Zn2+ conduction in insulating ZnPS3, demonstrating divalent ionic conductivity in an ordered, inorganic lattice near room temperature. Importantly, the activation energy associated with the bulk conductivity is low, 351 ± 99 meV, comparable to some Li+ conductors such as LTTO, although not as low as the superionic Li+ conductors. First-principles calculations suggest that the barrier corresponds to vacancy-mediated diffusion. Assessment of the structural distortions observed along the ion diffusion pathways suggests that an increase in the P-P-S bond angle in the [P2S6]4- moiety accommodates the Zn2+ as it passes through the high-energy intermediate coordination environments. ZnPS3 now represents a baseline material family to begin developing the structure-property relationships that control divalent ion diffusion and conduction in insulating solid-state hosts.
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U2 - 10.1021/acs.chemmater.9b00207
DO - 10.1021/acs.chemmater.9b00207
M3 - Article
AN - SCOPUS:85063083391
SN - 0897-4756
VL - 31
SP - 3652
EP - 3661
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 10
ER -