In-situ structure changes of ZIF based solid state electrolyte coin-cell batteries
Author
Andersen, Thor Bækgaard
Term
4. Term
Education
Publication year
2026
Submitted on
2026-05-31
Pages
31
Abstract
As renewable energy grows, the need for energy storage rises, and batteries are taking a larger share. However, today’s batteries face safety and scaling challenges, including dendrite formation (needle‑like lithium that can short‑circuit) and thermal runaway (uncontrolled overheating). Solid electrolytes could, in principle, limit these issues while increasing specific capacity. In this work, ZIF‑4 and ZIF‑62 were synthesized and pressed into electrolyte pellets for coin‑cell batteries. They currently show low overall ionic conductivity but a high lithium transference number, meaning a large fraction of the current is carried by Li+ ions. To see how they behave during operation, we performed in‑situ measurements on symmetric Li—QSSE—Li coin cells. The electrolyte’s crystal structure was unchanged during lithium‑ion transport. In contrast, the lithium metal electrodes changed under a small applied current, especially with ZIF‑4, where modifications were observed at the Li–QSSE interphase (the boundary between the lithium and the electrolyte).
I takt med at grøn vedvarende energi vokser, stiger behovet for at lagre energi, og batterier fylder mere i markedet. Dagens batterier har dog udfordringer med sikkerhed og skalering, bl.a. dendritdannelse (nåleformede lithiumstrukturer, der kan give kortslutning) og termisk runaway (ukontrolleret overophedning). Faste elektrolytter kan i princippet begrænse disse problemer og øge den specifikke kapacitet. I dette arbejde er ZIF-4 og ZIF-62 blevet syntetiseret og presset til elektrolyt‑pelletter til brug i møntcellebatterier. De udviser endnu lav samlet ionledningsevne, men har et højt lithium‑transference‑nummer, dvs. at en stor del af strømmen bæres af Li+-ioner. For at forstå deres opførsel under drift udførte vi in‑situ målinger på symmetriske Li—QSSE—Li møntceller. Resultaterne viser, at elektrolyttens krystalstruktur ikke påvirkes, når lithiumioner transporteres. Derimod sås ændringer i lithium‑elektrodernes struktur under pålagt svag strøm, især for ZIF-4, hvor der blev observeret ændringer ved Li–QSSE‑interfasen (grænsefladen mellem lithium og elektrolyt).
[This apstract has been rewritten with the help of AI based on the project's original abstract]