A two-dimensional (2D) silicene-germanene alloy, siligene (SixGey), a single-phase material, has attracted increased attention due to its two-elemental low-buckled composition and unique physics and chemistry. This 2D material has the potential to address the challenges caused by low electrical conductivity and the environmental instability of corresponding monolayers. Yet, the siligene structure was studied in theory, demonstrating the material's great electrochemical potential for energy storage applications. The synthesis of free-standing siligene remains challenging and therefore hinders the research and its application. Herein we demonstrate nonaqueous electrochemical exfoliation of a few-layer siligene from a Ca1.0Si1.0Ge1.0 Zintl phase precursor. The procedure was conducted in an oxygen-free environment applying a -3.8 V potential. The obtained siligene exhibits a high quality, high uniformity, and excellent crystallinity; the individual flake is within the micrometer lateral size. The 2D SixGey was further explored as an anode material for lithium-ion storage. Two types of anode have been fabricated and integrated into lithium-ion battery cells, namely, (1) siligene-graphene oxide sponges and (2) siligene-multiwalled carbon nanotubes. The as-fabricated batteries both with/without siligene exhibit similar behavior; however there is an increase in the electrochemical characteristics of SiGe-integrated batteries by 10%. The corresponding batteries exhibit a 1145.0 mAh·g-1 specific capacity at 0.1 A·g-1. The SiGe-integrated batteries demonstrate a very low polarization, confirmed by their good stability after 50 working cycles and a decrease in the solid electrolyte interphase level that occurs after the first discharge/charge cycle. We anticipate the growing potential of emerging two-component 2D materials and their great promise for energy storage and beyond.

Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica Facultad de Ciencias Universidad de Cádiz Campus Río San Pedro S N Puerto Real Cádiz 11510 Spain

Department of Engineering Faculty of Environment Science and Economy University of Exeter Exeter EX4 4QF United Kingdom

Department of Inorganic Chemistry University of Chemistry and Technology Prague Technická 5 166 28 Prague 6 Czech Republic

Instituto Universitario de Investigación de Microscopía Electrónica y Materiales Universidad de Cádiz Campus Río San Pedro S N Puerto Real Cádiz 11510 Spain

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Chen X.; Loaiza L. C.; Monconduit L.; Seznec V. 2D Silicon-Germanium-Layered Materials as Anodes for Li-Ion Batteries. ACS Appl. Energy Mater. 2021, 4, 12552–12561. 10.1021/acsaem.1c02362. DOI

Kasper E.; Herzog H. J. In Silicon–Germanium (SiGe) Nanostructures; Shiraki Y.; Usami N.Eds.; Woodhead Publishing: Oxford, 2011; pp 3–25.

Zemskov V. S.; Belokurova I. N.; Shulpina I. L.; Titkov A. N. The Structural Features of the Germanium-Silicon Solid Solution Crystals Obtained Under Microgravity. Adv. Space Res. 1984, 4, 11–14. 10.1016/0273-1177(84)90445-9. DOI

Dismukes J. P.; Ekstrom L.; Paff R. J. Lattice Parameter and Density in Germanium-Silicon Alloys. J. Phys. Chem. 1964, 68, 3021–3027. 10.1021/j100792a049. DOI

Zhang H.; Wang R. The Stability and the Nonlinear Elasticity of 2D Hexagonal Structures of Si and Ge from First-Principles Calculations. Phys. B: Conden. Matter 2011, 406, 4080–4084. 10.1016/j.physb.2011.07.052. DOI

Jamdagni P.; Kumar A.; Thakur A.; Pandey R.; Ahluwalia P. K. Stability and Electronic Properties of SiGe-based 2D Layered Structures. Mater. Res. Express 2015, 2, 01630110.1088/2053-1591/2/1/016301. DOI

Sannyal A.; Ahn Y.; Jang J. First-Principles Study on the Two-Dimensional Siligene (2D SiGe) as an Anode Material of an Alkali Metal Ion Battery. Comput. Mater. Sci. 2019, 165, 121–128. 10.1016/j.commatsci.2019.04.039. DOI

Mastail C.; Bourennane I.; Estève A.; Landa G.; Rouhani M. D.; Richard N.; Hémeryck A. Oxidation of Germanium and Silicon surfaces (100): A Comparative Study Through DFT Methodology. IOP Conf. Ser.: Mater. Sci. Eng. 2012, 41, 01200710.1088/1757-899X/41/1/012007. DOI

Kovalska E.; Antonatos N.; Luxa J.; Sofer Z. Edge-Hydrogenated Germanene by Electrochemical Decalcification-Exfoliation of CaGe2: Germanene-Enabled Vapor Sensor. ACS Nano 2021, 15, 16709–16718. 10.1021/acsnano.1c06675. PubMed DOI

Li P.; Cao J.; Guo Z.-X. A New Approach for Fabricating Germanene with Dirac Electrons Preserved: A First Principles Study. J. Mater. Chem. C 2016, 4, 1736–1740. 10.1039/C5TC03442F. DOI

Bianco E.; Butler S.; Jiang S.; Restrepo O. D.; Windl W.; Goldberger J. E. Stability and Exfoliation of Germanane: A Germanium Graphane Analogue. ACS Nano 2013, 7, 4414–4421. 10.1021/nn4009406. PubMed DOI

Cinquanta E.; Scalise E.; Chiappe D.; Grazianetti C.; van den Broek B.; Houssa M.; Fanciulli M.; Molle A. Getting Through the Nature of Silicene: an sp2–sp3 Two-Dimensional Silicon Nanosheet. J. Phys. Chem. C 2013, 117, 16719–16724. 10.1021/jp405642g. DOI

Giousis T.; Potsi G.; Kouloumpis A.; Spyrou K.; Geor-gantas Y.; Chalmpes N.; Dimos K.; Antoniou M.-K.; Papavassiliou G.; Bourlinos A. B.; Kim H. J.; Wadi J. K. Sh.; Alhassan S.; Ahmadi M.; Kooi B. J.; Blake G.; Balazs D. M.; Loi M. A.; Gournis D.; Rudolf P. Synthesis of 2D Germanane (GeH): A New, Fast, and Facile Approach. Angew. Chem., Int. Ed. 2021, 133 (1), 364–369. 10.1002/ange.202010404. PubMed DOI PMC

Muniz A. R.; Maroudas D. Opening and Tuning of Band Gap by the Formation of Diamond Superlattices in Twisted Bilayer Graphene. Phys. Rev. B 2012, 86, 07540410.1103/PhysRevB.86.075404. DOI

Gao R.; Tang J.; Yu X.; Lin S.; Zhang K.; Qin L.-C. Layered Silicon-Based Nanosheets as Electrode for 4 V High-Performance Supercapacitor. Adv. Funct. Mater. 2020, 30, 2002200.10.1002/adfm.202002200. DOI

Guo Q.; Han Y.; Chen N.; Qu L. Few-layer Siloxene as an Electrode for Superior High-Rate Zinc Ion Hybrid Capacitors. ACS Energy Lett. 2021, 6, 1786–1794. 10.1021/acsenergylett.1c00285. DOI

Liu J.; Yang Y.; Lyu P.; Nachtigall P.; Xu Y. Few-layer Silicene Nanosheets with Superior Lithium-Storage Properties. Adv. Mater. 2018, 30, 1800838.10.1002/adma.201800838. PubMed DOI

Wu B.; Šturala J.; Veselý M.; Hartman T.; Kovalska E.; Bouša D.; Luxa J.; Azadmanjiri J.; Sofer Z. Functionalized Germanane/SWCNT Hybrid Films as Flexible Anodes for Lithium-Ion Batteries. Nanoscale Adv. 2021, 3, 4440–4446. 10.1039/D1NA00189B. PubMed DOI PMC

Zhang Q.; Chen H.; Luo L.; Zhao B.; Luo H.; Han V.; Wang J.; Wang C.; Yang Y.; Zhu T.; Liu M. Harnessing the Concurrent Reaction Dynamics in Active Si and Ge to Achieve High Performance Lithium-Ion Batteries. Energy & Environ. Sci. 2018, 11, 669–681. 10.1039/C8EE00239H. DOI

Tian H.; Xin F.; Wang X.; He W.; Han W. High Capacity Group-IV Elements (Si, Ge, Sn) Based Anodes for Lithium-Ion Batteries. J. Materiomics 2015, 1, 153–169. 10.1016/j.jmat.2015.06.002. DOI

Heiskanen S. K.; Kim J.; Lucht B. L. Generation and Evolution of the Solid Electrolyte Interphase of Lithium-Ion Batteries. Joule 2019, 3, 2322–2333. 10.1016/j.joule.2019.08.018. DOI

Pender J. P.; Jha G.; Youn D. H.; Ziegler J. M.; Andoni I.; Choi E. J.; Heller A.; Dunn B. S.; Weiss P. S.; Penner R. M.; Mullins C. B. Electrode Degradation in Lithium-Ion Batteries. ACS Nano 2020, 14, 1243–1295. 10.1021/acsnano.9b04365. PubMed DOI

Hirel P. Atomsk: A Tool for Manipulating and Converting Atomic Data Files. Comput. Phys. Commun. 2015, 197, 212–219. 10.1016/j.cpc.2015.07.012. DOI

Glue-assisted exfoliation of two-dimensional sulfur-rich niobium thiophosphate (Nb4P2S21) for sulfur-equivalent electrode study in lithium storage

Electrochemical Exfoliation of Layered Non-van der Waals Crystals into 2D Nanosheets: MAX Phases and Beyond