Atomic/molecular layer deposition and electrochemical performance of dilithium 2-aminoterephthalate. Issue 5 (16th January 2020)

• Record Type: Journal Article
• Authors: Heiska, Juho; Nisula, Mikko; Rautama, Eeva-Leena; Karttunen, Antti J.; Karppinen, Maarit
• Is Part Of: Dalton transactions. Volume 49:Issue 5(2020)
• Page Start: 1591
• Page End: 1599
• Publication Date: 2020-01-16
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c9dt04572d
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Crystalline Li-terephthalate and amino-functionalized Li-terephthalate thin film electrodes are fabricated from gaseous precursors with ALD/MLD to show that the electron-donating amino group lowers the redox potential. Abstract : Control of the redox potential of lithium terephthalate Li2 TP anode material is demonstrated by functionalizing its terephthalate backbone with an electron-donating amino group; this lowers – as intended – the redox potential of Li2 TP by 0.14 V. The two Li-organic electrode materials, Li2 TP and Li2 TP-NH2, are fabricated as crystalline thin films from gaseous precursors using the atomic/molecular layer deposition (ALD/MLD) technique. The amino-functionalized material possesses a previously unknown crystal structure, addressed here by applying the USPEX evolutionary algorithm for the structure prediction and then LeBail fitting of the experimental XRD pattern based on the predicted structure model. The ALD/MLD fabrication yields in situ lithiated active electrode materials without any conductive additivies or binders and thus allows a straightforward evaluation of their intrinsic electrochemical properties. Comparison between Li2 TP and its amino-functionalized derivative reveals inferior capacity retention and rate capability characteristics for the latter, which somewhat counterveils the pros-and-cons balance between the two Li-organic electrode materials. From galvanostatic cycling experiments and post-mortem XRD and SEM analysis, the issue with Li2 TP-NH2 is revealed to be in the morphology changes occurring during the discharge/charge cycling.