{"title":"Compatibility between Li1.5Al0.5Ge1.5(PO4)3-based solid electrolyte and LiNi1/3Co1/3Mn1/3O2 cathode","authors":"S.V. Pershina","doi":"10.1016/j.ssi.2025.116896","DOIUrl":null,"url":null,"abstract":"<div><div>All-solid-state batteries (ASSBs) have a higher energy density and improved safety compared to traditional lithium-ion batteries. The problem of high interface resistance between the solid electrolyte and electrode materials needs to be addressed for the ASSBs production. Solid electrolytes of the Li<sub>1.5</sub>Al<sub>0.5</sub>Ge<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</sub> (LAGP) family with the NASICON-type structure possess a high lithium-ion conductivity and stability in air. In this work, Si-modified LAGP glass-ceramics (LAGSP) with a total Li<sup>+</sup> conductivity of 3·10<sup>−4</sup> S cm<sup>−1</sup> at 25 °C and a compact microstructure is considered. LiNi<sub>1/3</sub>Co<sub>1/3</sub>Mn<sub>1/3</sub>O<sub>2</sub> (NCM) is a promising cathode material which offers a high specific capacity and better cycle performance. Chemical interaction between the above-mentioned components at high temperature for the solid-solid interface creation was studied. The thermal behavior of the mechanical mixture of solid electrolyte and cathode material was studied by DSC method at temperatures of up to 900 °C. The phase composition of their mechanical mixture after heat treatment at different temperatures (500, 730 and 800 °C) was investigated by XRD. It was shown that the structure of the initial phases did not change after heat treatment at 500 °C. However, Li<sub>3</sub>PO<sub>4</sub>, Li<sub>4</sub>P<sub>2</sub>O<sub>7</sub>, NiAl<sub>2</sub>O<sub>4</sub> and GeO<sub>2</sub> phases begin to appear after annealing at 730 °C, while Co<sub>2</sub>MnO<sub>4</sub>, LiCoPO<sub>4</sub>, SiO<sub>2</sub>, GeO<sub>2</sub>, Li<sub>3</sub>PO<sub>4</sub> and Li<sub>9</sub>Al<sub>3</sub>(P<sub>2</sub>O<sub>7</sub>)<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> formation was observed at 800 °C. Heating at 800 °C leads to a complete degradation of the solid electrolyte. Therefore, it was proposed to create a LAGSP | NCM interface using a liquid electrolyte. LiPF<sub>6</sub>-based liquid electrolyte was used as a buffer layer between solid electrolyte and cathode for enhancing the interfacial contact. Symmetrical NCM | solid electrolyte | NCM and NCM |LiPF<sub>6</sub> | solid electrolyte | LiPF<sub>6</sub> | NCM cells are assembled and their resistance at room temperature is measured. It was established that modified cells had the lowest resistance at room temperature (1.2 kΩ·cm<sup>2</sup>) compared to unmodified cells (162 kΩ·cm<sup>2</sup>).</div></div>","PeriodicalId":431,"journal":{"name":"Solid State Ionics","volume":"427 ","pages":"Article 116896"},"PeriodicalIF":3.0000,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Solid State Ionics","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167273825001158","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
All-solid-state batteries (ASSBs) have a higher energy density and improved safety compared to traditional lithium-ion batteries. The problem of high interface resistance between the solid electrolyte and electrode materials needs to be addressed for the ASSBs production. Solid electrolytes of the Li1.5Al0.5Ge1.5(PO4)3 (LAGP) family with the NASICON-type structure possess a high lithium-ion conductivity and stability in air. In this work, Si-modified LAGP glass-ceramics (LAGSP) with a total Li+ conductivity of 3·10−4 S cm−1 at 25 °C and a compact microstructure is considered. LiNi1/3Co1/3Mn1/3O2 (NCM) is a promising cathode material which offers a high specific capacity and better cycle performance. Chemical interaction between the above-mentioned components at high temperature for the solid-solid interface creation was studied. The thermal behavior of the mechanical mixture of solid electrolyte and cathode material was studied by DSC method at temperatures of up to 900 °C. The phase composition of their mechanical mixture after heat treatment at different temperatures (500, 730 and 800 °C) was investigated by XRD. It was shown that the structure of the initial phases did not change after heat treatment at 500 °C. However, Li3PO4, Li4P2O7, NiAl2O4 and GeO2 phases begin to appear after annealing at 730 °C, while Co2MnO4, LiCoPO4, SiO2, GeO2, Li3PO4 and Li9Al3(P2O7)3(PO4)2 formation was observed at 800 °C. Heating at 800 °C leads to a complete degradation of the solid electrolyte. Therefore, it was proposed to create a LAGSP | NCM interface using a liquid electrolyte. LiPF6-based liquid electrolyte was used as a buffer layer between solid electrolyte and cathode for enhancing the interfacial contact. Symmetrical NCM | solid electrolyte | NCM and NCM |LiPF6 | solid electrolyte | LiPF6 | NCM cells are assembled and their resistance at room temperature is measured. It was established that modified cells had the lowest resistance at room temperature (1.2 kΩ·cm2) compared to unmodified cells (162 kΩ·cm2).
期刊介绍:
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