Study of Solid State Lithium Batteries with a Ceramic Electrolyte

Solid state lithium batteries are considered as the next generation of batteries due to its potential higher energy density and better safety compared to Li-ion technology[1]. Oxides, sulfides, polymers and polymer/ceramic hybrid materials can be used as lithium ion conducting solid electrolytes, some of which have very good ionic conductivities (up to 10-3 S.cm-1 at 25°C) and good electrochemical stability[2,3]. Li1,3Al0,3Ti1,7(PO4)3 (LATP) is a potential candidate as a solid electrolyte with an ionic conductivity of 1.10-4 S.cm-1 at 25°C. It is stable up to 5V vs Li/Li+ but it is instable in contact with lithium due to the reduction of Ti4+ in Ti3+ [4]. A thin protective layer of a stable lithium ion conducting material is deposited to avoid contact between LATP and Li metal[5]. The LATP solid electrolyte has been synthesized via solid state synthesis and LATP particles exhibit a cubic morphology. Al doped Li7La3Z2O12 (LLZO), another good candidate for solid electrolyte, displays a high ionic conductivity >10-4 S.cm-1 [6] and an good stability in contact with lithium metal. LLZO synthesized by the Pechini route exhibit a cubic phase with minor impurity of La2Zr2O7. The main challenge is to control this interphase in order to decrease the interfacial resistance. Different strategies are employed to deposit the lithium such as electrochemical deposition and vapor deposition. Full cells are assembled using different positive electrode compositions and characterized in order to overcome the technological barriers related to this technology. [1] T. Placke, R. Kloepsch, S. Dühnen, M. Winter, Lithium ion, lithium metal, and alternative rechargeable battery technologies: the odyssey for high energy density, J. Solid State Electrochem. 21 (2017) 1939–1964. doi:10.1007/s10008-017-3610-7. [2] J. Janek, W.G. Zeier, A solid future for battery development, Nat. Energy. 1 (2016) 1–4. doi:10.1038/nenergy.2016.141. [3] Y. Zhu, X. He, Y. Mo, Origin of Outstanding Stability in the Lithium Solid Electrolyte Materials: Insights from Thermodynamic Analyses Based on First-Principles Calculations, ACS Appl. Mater. Interfaces. 7 (2015) 23685–23693. doi:10.1021/acsami.5b07517. [4] P. Hartmann, T. Leichtweiss, M.R. Busche, M. Schneider, M. Reich, J. Sann, P. Adelhelm, J. Janek, Degradation of NASICON-type materials in contact with lithium metal: Formation of mixed conducting interphases (MCI) on solid electrolytes, J. Phys. Chem. C. 117 (2013) 21064–21074. doi:10.1021/jp4051275. [5] H.S. Kim, Y. Oh, K.H. Kang, J.H. Kim, J. Kim, C.S. Yoon, Characterization of Sputter-Deposited LiCoO 2 Thin Film Grown on NASICON-type Electrolyte for Application in All-Solid-State Rechargeable Lithium Battery, ACS Appl. Mater. Interfaces. 9 (2017) 16063–16070. doi:10.1021/acsami.6b15305. [6] R. Murugan, V. Thangadurai, W. Weppner, Fast lithium ion conduction in garnet-type Li7La 3Zr2O12, Angew. Chemie - Int. Ed. 46 (2007) 7778–7781. doi:10.1002/anie.200701144. Figure 1