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A high-energy Li-ion battery using a silicon-based anode and a nano-structured layered composite cathode. Adv. Func. Mater. 24, 3036–3042 (2014). Acknowledgements R.R., A.V. and S.P. acknowledge the financial support of Bundesministerium für Bildung und Forschung (BMBF) within the project ‘IES, Innovative Elektrochemische Superkondensatoren’ (contract number 03EK3010). B.S. is grateful to the Helmholtz Institute Ulm for a six-month visiting professorship position. Author contributions R.R. and A.V. designed the outline of the Progress Article, wrote the manuscript and conceived the figures and tables. S.P. and B.S. supervised and revised the writing. Additional information Reprints and permissions information is available online at www.nature.com/reprints. Correspondence should be addressed to S.P. or B.S. Competing financial interests The authors declare no competing financial interests. NATURE MATERIALS DOI: 10.1038/NMAT4170 PROGRESS ARTICLE © 2014 Macmillan Publishers Limited. 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