Abstract
Binary metal oxides have received sustained interest as anode materials due to their desirable capacities, exceeding theoretical values particularly in the first discharge. Although they have received increasing attention in recent years, topical debates persist regarding not only their lithiation mechanisms but also the origin of additional capacity. Aiming to resolve these disagreements, we perform a systematic study of a series of iron and manganese oxides to investigate their phase behavior during first discharge. Using a combination of in operando pair distribution function measurements and our recently developed Metropolis non-negative matrix factorization approach to address the analytical challenges concerning materials’ nanoscopic nature and phase heterogeneity, here we report unexpected observation of non-equilibrium FeOx solid-solution phases and pulverization of MnO. These processes are correlated with the extra capacities observed at different depths of discharge, pointing to a metal-dependent nature of this additional capacity and demonstrating the advantage of our approach with promising prospects for diverse applications.
| Original language | English |
|---|---|
| Article number | 100543 |
| Journal | Cell Reports Physical Science |
| Volume | 2 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 22 2021 |
Funding
This work was supported by European Commission via MSCA-IF-2020 . The use of Diamond Light Source for access to beamline I15-1 (XPDF) is under proposal CY22115-1 . X.H. acknowledges funding from the European Commission via MSCA (grant 798169 , DisorMetox). P.K.A. acknowledges a Birmingham Fellowship from the University of Birmingham . H.S.G. is supported by EPSRC via a CASE studentship and Faraday Challenge project FutureCat (grant FIRG017 ). E.C.-M. acknowledges funding from RTI2018-094550-A-I00 from MICINN . P.G.B. is indebted to the EPSRC for financial support, including a program grant, to the Faraday Institution and the Sir Henry Royce Institute . A.L.G. and A.M. acknowledge funding from the ERC (grant 788144 ). The authors also acknowledge helpful discussion and comments from E. Reynolds, E. Schmidt, R. House, D. Forstermann, C. Gong, S. Booth, S. Corr, and S. Dutton. This work was supported by European Commission via MSCA-IF-2020. The use of Diamond Light Source for access to beamline I15-1 (XPDF) is under proposal CY22115-1. X.H. acknowledges funding from the European Commission via MSCA (grant 798169, DisorMetox). P.K.A. acknowledges a Birmingham Fellowship from the University of Birmingham. H.S.G. is supported by EPSRC via a CASE studentship and Faraday Challenge project FutureCat (grant FIRG017). E.C.-M. acknowledges funding from RTI2018-094550-A-I00 from MICINN. P.G.B. is indebted to the EPSRC for financial support, including a program grant, to the Faraday Institution and the Sir Henry Royce Institute. A.L.G. and A.M. acknowledge funding from the ERC (grant 788144). The authors also acknowledge helpful discussion and comments from E. Reynolds, E. Schmidt, R. House, D. Forstermann, C. Gong, S. Booth, S. Corr, and S. Dutton. X.H. conceived the study. X.H. planned the project with help from P.K.A. and A.L.G. X.H. prepared the materials and analyzed the electrochemical data with help from P.K.A. and support from A.M. E.C.-M. and P.G.B. X.H. and P.K.A. carried out the in situ PDF experiments with help from P.A.C. X.H. performed NMF analysis with help from H.S.G. T.S.D. and A.L.G. The manuscript was written by X.H. and revised by E.C.-M. and A.L.G. All authors contributed to discussions and commented on the manuscript. The authors declare no competing interests.
Keywords
- lithium-ion batteries
- metal oxide anodes
- mixed-phase deconvolution
- pair distribution function