Characterization and Optimization of Co-Doped SnO2 As Anode for Lithium-Ion Batteries

Tin oxide-based materials have been intensively investigated as alternative anodes for lithium-ion batteries due to their high specific capacity, environmental friendliness, non-toxicity, and ease of handling.[1] However, the initial formation of Li2O upon lithiation is essentially irreversible, which has a severe effect on the first cycle coulombic efficiency and the reversibly achievable capacity in general.[2] It has been shown that the incorporation of transition metal dopants can address this issue, as it enables the reversible formation and reformation of Li2O.[3] The choice of the dopant, however, plays a critical role for the long-term cycling stability, rate capability, and eventual energy density of the resulting lithium-ion cells.[4] Herein, we show that the addition of specific combination of different dopants allows for further tailoring the electrochemical properties. We also demonstrate the production of such materials using a scalable continuous hydrothermal flow method. The performance of the best composition (Sn0.9Co0.05Mn0.05O2, SCMO) was further improved by applying a carbonaceous coating. The electrochemical investigation of the coated anode material was conducted in half-cells and in high-energy full-cells using high-voltage LiNi0.5Mn1.5O4 (LNMO) as active material for the cathode (Figure 1).[5] The performance of the full-cells was further enhanced by carefully optimizing the anode composition and fine-tuning the full-cell design, considering electrolytes and different pre-lithiation degrees. Reference s : [1] F. Zoller, D. Böhm, T. Bein, D. Fattakhova-Rohlfing, ChemSusChem., 1 2 , 4140 (2019) [2] I.A. Courtney and J.R. Dahn, J Electrochemical Soc., 144 , 2045 (1997) [3] D. Bresser, S. Passerini and B. Scrosati, Energy Environ. Sci. , 9 , 3348 (2016) [4] Y. Ma et al, Sustain. Energy Fuels, 2 , 2601 (2018) [5] A. Birrozzi et al., Batter. Supercaps, 3 , 284 (2020). Figure 1