Germanium, with a high theoretical capacity based on alloyed lithium and germanium (1384 mA h g-1 Li15Ge4), has stimulated tremendous research as a promising candidate anode material for lithium-ion batteries (LIBs). However, due to the alloying reaction of Li/Ge, the problems of inferior cycle life and massive volume expansion of germanium are equally obvious. Among all Ge-based materials, the unique layered 2D germanane (GeH and GeCH3) with a graphene-like structure, obtained by a chemical etching process from the Zintl phase CaGe2, could enable storage of large quantities of lithium between their interlayers. Besides, the layered structure has the merit of buffering the volume expansion due to the tunable interlayer spacing. In this work, the beyond theoretical capacities of 1637 mA h g-1 for GeH and 2048 mA h g-1 for GeCH3 were achieved in the initial lithiation reaction. Unfortunately, the dreadful capacity fading and electrode fracture happened during the subsequent electrochemical process. A solution, i.e. introducing single-wall carbon nanotubes (SWCNTs) into the structure of the electrodes, was found and further confirmed to improve their electrochemical performance. More noteworthy is the GeH/SWCNT flexible electrode, which exhibits a capacity of 1032.0 mA h g-1 at a high current density of 2000 mA g-1 and a remaining capacity of 653.6 mA h g-1 after 100 cycles at 500 mA g-1. After 100 cycles, the hybrid germanane/SWCNT electrodes maintained good integrity without visible fractures. These results indicate that introducing SWCNTs into germanane effectively improves the electrochemical performance and maintains the integrity of the electrodes for LIBs.

Department of Inorganic Chemistry University of Chemistry and Technology Prague Technick'a 5 166 28 Prague Czech Republic

Department of Organic Technology University of Chemistry and Technology Prague Technicka 5 166 28 Prague Czech Republic

See more in PubMed

Saverina E. A. Sivasankaran V. Kapaev R. R. Galushko A. S. Ananikov V. P. Egorov M. P. Jouikov V. V. Troshin P. A. Syroeshkin M. A. Green Chem. 2020;22:359–367.

Qiu L. Xiang W. Tian W. Xu C.-L. Li Y.-C. Wu Z.-G. Chen T.-R. Jia K. Wang D. He F.-R. Nano Energy. 2019;63:103818.

Lee S.-H. Lee S. Jin B.-S. Kim H.-S. Sci. Rep. 2019;9:1–7. PubMed

Chao D. Xia X. Liu J. Fan Z. Ng C. F. Lin J. Zhang H. Shen Z. X. Fan H. J. Adv. Mater. 2014;26:5794–5800. PubMed

Liu K. Yang S. Luo L. Pan Q. Zhang P. Huang Y. Zheng F. Wang H. Li Q. Electrochim. Acta. 2020:136856.

Heng S. Shan X. Wang W. Wang Y. Zhu G. Qu Q. Zheng H. Carbon. 2020;159:390–400.

Moradi B. Botte G. G. J. Appl. Electrochem. 2016;46:123–148.

Natarajan S. Aravindan V. Adv. Energy Mater. 2020:2002238.

Liu Z. Yu Q. Zhao Y. He R. Xu M. Feng S. Li S. Zhou L. Mai L. Chem. Soc. Rev. 2019;48:285–309. PubMed

Lu J. Chen Z. Pan F. Cui Y. Amine K. Electrochem. Energy Rev. 2018;1:35–53.

Cui G. Gu L. Zhi L. Kaskhedikar N. v. van Aken P. A. Müllen K. Maier J. Adv. Mater. 2008;20:3079–3083.

Cui L.-F. Yang Y. Hsu C.-M. Cui Y. Nano Lett. 2009;9:3370–3374. PubMed

Liu Y. Zhang N. Jiao L. Tao Z. Chen J. Adv. Funct. Mater. 2015;25:214–220.

Cho Y. J. Im H. S. Kim H. S. Myung Y. Back S. H. Lim Y. R. Jung C. S. Jang D. M. Park J. Cha E. H. ACS Nano. 2013;7:9075–9084. PubMed

Pathak A. D. Chanda U. K. Samanta K. Mandal A. Sahu K. K. Pati S. Electrochim. Acta. 2019;317:654–662.

Sun X. Lu X. Huang S. Xi L. Liu L. Liu B. Weng Q. Zhang L. Schmidt O. G. ACS Appl. Mater. Interfaces. 2017;9:38556–38566. PubMed

Liu X. Wu X.-Y. Chang B. Wang K.-X. Energy Storage Mater. 2020;30:146–169.

Xiao X. Li X. Zheng S. Shao J. Xue H. Pang H. Adv. Mater. Interfaces. 2017;4:1600798.

Serino A. C. Ko J. S. Yeung M. T. Schwartz J. J. Kang C. B. Tolbert S. H. Kaner R. B. Dunn B. S. Weiss P. S. ACS Nano. 2017;11:7995–8001. PubMed

Yan Y. Ruan J. Xu H. Xu Y. Pang Y. Yang J. Zheng S. ACS Appl. Mater. Interfaces. 2020;12:21579–21585. PubMed

Li W. Yang Z. Cheng J. Zhong X. Gu L. Yu Y. Nanoscale. 2014;6:4532–4537. PubMed

Tan L. P. Lu Z. Tan H. T. Zhu J. Rui X. Yan Q. Hng H. H. J. Power Sources. 2012;206:253–258.

Park M. H. Cho Y. Kim K. Kim J. Liu M. Cho J. Angew. Chem., Int. Ed. 2011;50:9647–9650. PubMed

Wang X. Susantyoko R. A. Fan Y. Sun L. Xiao Q. Zhang Q. Small. 2014;10:2826–2829. PubMed

Park M. H. Kim K. Kim J. Cho J. Adv. Mater. 2010;22:415–418. PubMed

Liu S. Feng J. Bian X. Qian Y. Liu J. Xu H. Nano Energy. 2015;13:651–657.

Liang J. Li X. Hou Z. Zhang T. Zhu Y. Yan X. Qian Y. Chem. Mater. 2015;27:4156–4164.

Gao X. Luo W. Zhong C. Wexler D. Chou S.-L. Liu H.-K. Shi Z. Chen G. Ozawa K. Wang J.-Z. Sci. Rep. 2014;4:6095. PubMed PMC

Ren J.-G. Wu Q.-H. Tang H. Hong G. Zhang W. Lee S.-T. J. Mater. Chem. A. 2013;1:1821–1826.

Wang J. Wang J.-Z. Sun Z.-Q. Gao X.-W. Zhong C. Chou S.-L. Liu H.-K. J. Mater. Chem. A. 2014;2:4613–4618.

Chen K.-S. Balla I. Luu N. S. Hersam M. C. ACS Energy Lett. 2017;2:2026–2034.

Shi L. Zhao T. J. Mater. Chem. A. 2017;5:3735–3758. PubMed

Loaiza L. C. Monconduit L. Seznec V. J. Power Sources. 2019;417:99–107.

Weiss A. Beil G. Meyer H. Z. Naturforsch., B: Anorg. Chem., Org. Chem. 1980;35:25–30.

Loaiza L. C. Monconduit L. Seznec V. Small. 2020;16:1905260. PubMed

Hartman T. Sofer Z. ACS Nano. 2019;13:8566–8576. PubMed

Li Y. Chen Z. J. Phys. Chem. C. 2014;118:1148–1154.

Jiang S. Butler S. Bianco E. Restrepo O. D. Windl W. Goldberger J. E. Nat. Commun. 2014;5:1–6. PubMed

Madhushankar B. N. Kaverzin A. Giousis T. Potsi G. Gournis D. Rudolf P. Blake G. R. Van Der Wal C. H. Van Wees B. J. 2D Mater. 2017;4:021009.

Zhao F. Wang Y. Zhang X. Liang X. Zhang F. Wang L. Li Y. Feng Y. Feng W. Carbon. 2020;161:287–298.

Loaiza L. C. Monconduit L. Seznec V. Batteries Supercaps. 2020;3:417–426.

Hartman T. Sturala J. Luxa J. Sofer Z. ACS Nano. 2020;14:7319–7327. PubMed

Sturala J. Luxa J. Matějková S. Plutnar J. Hartman T. Pumera M. Sofer Z. Chem. Mater. 2019;31:10126–10134.

Liu Z. Wang Z. Sun Q. Dai Y. Huang B. Appl. Surf. Sci. 2019;467:881–888.

Hod O. J. Chem. Theory Comput. 2012;8:1360–1369. PubMed

Cultrara N. D. Arguilla M. Q. Jiang S. Sun C. Scudder M. R. Ross R. D. Goldberger J. E. Beilstein J. Nanotechnol. 2017;8:1642–1648. PubMed PMC

Liu Z. Wang Z. Sun Q. Dai Y. Huang B. Appl. Surf. Sci. 2019;467–468:881–888.

Hartman T. Sturala J. Plutnar J. Sofer Z. Angew. Chem., Int. Ed. 2019;58:16517–16522. PubMed

Wei L. Hou Z. Wei H. Electrochim. Acta. 2017;229:445–451.

Bogart T. D. Chockla A. M. Korgel B. A. Curr. Opin. Chem. Eng. 2013;2:286–293.

DiLeo R. A. Frisco S. Ganter M. J. Rogers R. E. Raffaelle R. P. Landi B. J. J. Phys. Chem. C. 2011;115:22609–22614.

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

Electrochemical Decalcification-Exfoliation of Two-Dimensional Siligene, SixGey: Material Characterization and Perspectives for Lithium-Ion Storage