Dr. Denis Y.W. YU

PhD in Applied Physics, School of Engineering and Applied Sciences, Harvard University

Assistant Professor (School of Energy and Environment)

Dr. Denis YU

Contact Information

Office: YEUNG-B5422
Phone: +(852)-3442-6885
Fax: +(852)-3442-0688
Email: denisyu@cityu.edu.hk
Webpage: BEST Lab homepage
Time slots for consultation

Research Interests

  • effect of size on electrochemical performance
  • nano-architecturing of battery materials
  • understanding effect of electrode configuration and electrolyte
  • high voltage battery materials
  • mechanical properties of battery materials
  • novel sodium-ion battery materials

Dr. Denis Yu received his A.B. (Physics) in 1995 from Princeton University and PhD in 2003 (Applied Physics) from Harvard University. After completing his PhD, he moved to Japan to work as an engineer at the Energy R&D Laboratory at SANYO Electric Co. Ltd., developing cathode and anode materials for Li-ion batteries. In mid 2011, he joined the Energy Research Institute at Nanyang Technological University, Singapore, leading the battery and energy storage effort, as well as serving as a co-PI at the TUM CREATE Centre for Electromobility. In June 2013, he joined the City University of Hong Kong as an assistant professor.

Research Interests:

Dr. Yu’s research focus is on studying materials for energy storage, centering on examining the effect of surface chemistry and structure on electrochemical performance, as well as on the long-term stability and safety of materials for batteries and supercapacitors. Topics of interest includes

  • effect of size on electrochemical performance
  • nano-architecturing of battery materials
  • understanding effect of electrode configuration and electrolyte
  • high voltage battery materials
  • mechanical properties of battery materials
  • novel sodium-ion battery materials

Positions Available

PhD candidate

Potential graduate students interested in studying battery mechanisms are welcomed to contact Dr. Denis Yu. Applicants will have to go through a centralized admission process through the City University of Hong Kong. The next intake of graduate student will be for the academic year starting from September 2019.

Research assistant/fellow to develop materials for supercapacitors

Duties: perform laboratory work to construct, test and analyze supercapacitors
Requirement: prior experience with research on supercapacitors
Application: please send cover letter, CV to Dr. Denis Yu at denisyu@cityu.edu.hk

Selected Journal Publications

  1. D . Sehrawat, J. Zhang, D. Y. W. Yu*, N. Sharma* “In situ studies of Li/Cu doped layered P2 NaxMnO2 electrodes for sodium ion batteries” Small Methods (2018) in press.
  2. J. Zhang, D. Y. W. Yu* “Stabilizing Na0.7MnO2 cathode for Na-ion battery via a single-step surface coating and doping process” J. Power Sources (2018) in press.  
  3. C. Y. Chan, P.-K. Lee, Z. Xu, D. Y. W. Yu* “Designing high-power graphite-based dual-ion batteries” Electrochim. Acta (2018) 263, 34-39.
  4. X. Yang, H. Wang, D. Y. W. Yu*, A. L. Rogach* “Vacuum calcination induced conversion of selenium/carbon wires to tubes for high-performance sodium-selenium batteries” Adv. Funct. Mater. (2018) 1706609. DOI: 10.1002/adfm.201706609
  5. B. Su, H. Liang, G. Liu, Z. Huang, X. Liu, Z. Chen, D. Y. W. Yu “Damage development of sintered SiC ceramics with the depth variation in Ar ion-irradiation at 600 °C” J. Eur. Ceramic Soc. (2018) in press.
  6. X. Yang, J. Zhang, Z. Wang, H. Wang, C. Zhi, D. Y. W. Yu*, A. L. Rogach* “Carbon-supported nickel selenide hollow nanowires as advanced anode materials for sodium-ion batteries” Small (2017) 1702669. DOI: 10.1002/smll.201702669
  7. H. Bian, R. Dong, Q. Shao, S. Wang, M.-F. Yuen, Z. Zhang, D. Y. W. Yu, W. Zhang, J. Lu, Y. Y. Li “Water-enabled crystallization of mesoporous SnO2 as binder-free electrode for enhanced sodium storage” J. Mater. Chem. A (2017) 5, 23967-23975.
  8. Y. Li, S. Wang, P.-K. Lee, J. He, D. Y. W. Yu* “Crack-resistant polyimide coating for high-capacity battery anodes” J. Power Sources (2017) 366, 226-232.
  9. W. Wang, J. Zhang, D. Y. W. Yu, Q. Li “Improving the cycling stability of Sn4P3 anode for sodium-ion battery” J. Power Sources (2017) 364, 420-425. 
  10. A. G. Medvedev, A. A. Mikhaylov, D. A. Grishanov, D. Y. W. Yu, J. Gun, S. Sladkevich, O. Lev, P. V. Prikhodchenko “GeO2 Thin Film Deposition on Graphene Oxide by the Hydrogen Peroxide Route: Evaluation for Lithium-Ion Battery Anode” ACS Appl. Mater. Interfaces (2017) 9, pp 9152–9160.
  11. J. Zhang, D. Y. W. Yu* “Phase-pure P2-Na0.7(1-x)[LixMn1-x]Oδ as cathode material for Na-ion batteries” ChemElectroChem (2017) 4, 1287-1294. DOI: 10.1002/celc.201700054.
  12. J. Zhang, W. Kang, M. Jiang, Y. You, Y. Cao, T.-W. Ng, D. Y. W. Yu, C.-S. Lee, J. Xu “Conversion of 1T-MoSe2 to 2H-MoS2:XSe2-2 x mesoporous nanospheres for superior sodium storage performance” Nanoscale (2017) 9, 1484-1490.
  13. H. Bian, X. Xiao, S. Zeng, M.-F. Yuen, Z. Li, W. Kang, D. Y. W. Yu, Z. Xu, J. Lu, Y. Y. Li “Mesoporous C-coated SnOx nanosheets on copper foil as flexible and binder-free anodes for superior sodium-ion batteries” J. Mater. Chem. A (2017) 5, 2243-2250.
  14. P.-K. Lee, Y. Li, D. Y. W. Yu* “Insights from studying the origins of reversible and irreversible capacities on silicon electrodes” J. Electrochem. Soc. (2017) 164, A6206-A6212.
  15. W. Kang, D. Y. W. Yu*, P.-K. Lee, Z. Zhang, H. Bian, W. Li, T.-W. Ng, W. Zhang, C.-S. Lee “P2-Type NaxCu0.15Ni0.20Mn0.65O2 Cathodes with High Voltage for High-Power and Long-Life Sodium-Ion Batteries” ACS Appl. Mater. Interfaces (2016) 8, 31661-31668. DOI: 10.1021/acsami.6b10841
  16. X. Gong, G. Liu, Y. Li, D.Y.W. Yu, W.Y. Teoh. “Functionalized-graphene composites: Fabrication and applications in sustainable energy and environment” Chem. Mater. (2016) 28, 8082-8118.
  17. Z.-T. Shi, W. Kang, J. Xu, Y.-W. Sun, M. Jiang, T.-W. Ng, H.-T. Xue, D.Y.W. Yu, W. Zhang, C.-S. Lee. “Hierarchical nanotubes assembled from MoS2-carbon monolayer sandwiched superstructure nanosheets for high-performance sodium ion batteries”, 
    Nano Energy (2016) 4, 27-37.
  18. H. Bian, J. Zhang, M.-F. Yuen, W. Kang, Y. Zhan, D.Y.W. Yu, Z. Xu and Y. Y. Li. “Anodic nanoporous SnO2 grown on Cu foils as superior binder-free Na-ion battery anodes”, J. Power Sources (2016) 307, 634-640.
  19. H. Zhou, Y. Li, J. Zhang, W. Kang and D.Y.W. Yu*, “Low-temperature one-step synthesis of layered m-LiMnO2 for lithium-ion battery applications”, Journal of Alloys and Compounds (2016) 659, 248-254. DOI: 10.1016/j.jallcom.2015.11.038
  20. J. Zhang, W. Wang, Y. Li and D.Y.W. Yu* “Sodium storage capability of spinel Li4Mn5O12”, Electrochimica Acta (2015) 185, 76-82. DOI: 10.1016/j.electacta.2015.10.101
  21. Hongtao Xue, Denis Y.w. Yu, Jian Qing, Xia Yang, Jun Xu, Zhangpeng Li, MingliangW. Kang, Z. Zhang, P.-K. Lee, T.-W. Ng, W. Li, Y. Tang, W. Zhang, C.-S. Lee and D.Y.W. Yu* “Copper substituted P2-type Na0.67CuxMn1-xO2: a stable high-power sodium-ion battery cathode”, Journal of Materials Chemistry A (2015) 3, 22846-22852. DOI: 10.1039/c5ta06371j.
  22. Z.-T. Shi, W. Kang, J. Xu*, L.-Lu. Sun, C. Wu, L. Wang, Y.-Q. Yu, D.Y.W. Yu*, W. Zhang and C.-S. Lee*, “In-situ carbon doped Mo(Se0.85S0.15)2 hierarchical nanotubes as stable anode for high performance sodium-ion batteries”, Small (2015) 11, 5667-5674. DOI: 10.1002/smll.201501360
  23. W. Kang, D.Y.W. Yu, W. Li, Z. Zhang, X. Yang, T.-W. Ng, R. Zou, Y. Tang, W. Zhang and C.-S. Lee, “Nanostructured porous manganese carbonate spheres with capacitive effects on the high lithium storage capability”, Nanoscale (2015) 7, 10146-10151. DOI: 10.1039/C5NR01843A
  24. D.Y.W. Yu*, M. Zhao and H. E. Hoster “Suppressing vertical displacement of lithiated silicon particles in high volumetric capacity battery electrodes”, ChemElectroChem (2015) 2, 1090-1095. DOI: 10.1002/celc.201500133
  25. H. Xue, D.Y.W. Yu, J. Qing, X. Yang, J. Xu, Z. Li, M. Sun, W. Kang, Y. Tang and C.-S. Lee, “Pyrite FeS2 microspheres wrapped by reduced graphene oxide as high-performance lithium-ion battery anodes” J. Mater. Chem. A (2015) 3, 7945-7949. DOI: 10.1039/C5TA00988J.
  26. D.Y.W. Yu, S. K. Batabyal, J. Gun, S. Sladkevich, A. A. Miklaylov, A. G. Medvedev, V. M. Novotortsev, O. Lev and P. V. Prikhodchenko, “Antimony and antimony oxide@graphene oxide obtained by the peroxide route as anodes for lithium-ion batteries”, Main Group Met. Chem. (2015) 38, 43.
  27. J. Geder, J. H. Song, S. H. Kang and D.Y.W. Yu*, “Thermal stability of lithium-rich manganese-based cathode”, Solid State Ionics (2014) 268, 242-246.
  28. A. Nagasubramanian, D.Y.W. Yu, H. Hoster and M. Srinivasan “Enhanced cycling stability of o-LiMnO2 cathode modified by lithium boron oxide coating for lithium-ion batteries”, J. Solid State Electrochem. (2014) 18, 1915-1922. DOI 10.1007/s10008-014-2421-3
  29. P. V. Prikhodchenko, D.Y.W. Yu*, S. K. Batabyal, V. Uvarov, J. Gun, S. Sladkevich, A. A. Miklaylov, A. G. Medvedev and O. Lev, “Nanocrystalline tin disulfide coating of reduced graphene oxide produced by the peroxostannate deposition route for sodium ion battery anodes”, J. Mater. Chem. A (2014) 2, 8431-8437. Doi:10.1039/c3ta15248k
  30. D.Y.W.Yu*, Harry E. Hoster and S.K. Batabyal, “Bulk antimony sulfide with excellent cycle stability as next-generation anode for lithium-ion batteries”, Scientific Reports (2014) 4:4562. doi:10.1038/srep04562
  31. N. Bucher, S. Hartung, D.Y.W. Yu, M. Arkhipova, P. Kratzer, G. Maas, M. Srinivasan and H. E. Hoster, “A novel ionic liquid for Li ion batteries – uniting the advantages of guanidinium and piperidinium”, RSC Advances (2014) 4, 1996-2003.
  32. A. Rinaldi, O. Wijaya, H. Hoster and D.Y.W. Yu* “How seeding influences discharge capacities of Li-O2 batteries (history effect in Li-O2 battery)”, Chem. Sus. Chem. (2014) 7, 1283-1288. DOI: 10.1002/cssc.201300986
  33. J. Geder, H. E. Hoster, A. Jossen, J. Garche and D.Y.W.Yu* “Impact of active material surface area on thermal stability of LiCoO2 cathode”, J. Power Sources (2014) 257, 286-292.
  34. D.Y.W. Yu*, R. L. Lee, R. Yi, S. Y. Chiam and P. D. Tran, “Electrochemical characterization of novel layered Cu2MS4 materials for Li-ion batteries (M = Mo)”, Electrochim. Acta (2014), 115, 337-343.
  35. C.W. Mason, I.D. Gocheva, H.E. Hoster and D.Y.W. Yu “Iron (III) sulfate:  a stable, cost effective electrode material for sodium ion batteries”, Chem. Comm. (2014) 50, 2249-2251. DOI:10.1039/C3CC47557C.
  36. D.Y.W. Yu*, P.V. Prikhodchenko, C.W. Mason, S.K. Batabyal, J. Gun, S. Sladkevich, A. Medvedev and O. Lev, “High-capacity antimony sulphide nanoparticle-decorated graphene composite as anode for sodium-ion batteries” Nature Communications (2013) 4:2922. DOI: 10.1038/ncomms3922.
  37. L.F. Lai, J. Zhu, Z. Li, D.Y.W. Yu, S. Jiang, X. Cai, Q. Yan, Y. M. Lam, Z. Shen and J. Lin, “Co3O4/nitrogen modified graphene electrode as Li-ion battery anode with high reversible capacity and improved initial cycle performance”, Nano Energy (2014) 3, 134-143. http://dx.doi.org/10.1016/j.nanoen.2013.05.014.
  38. H. Yu, X. Rui,H. Tan, J. Chen, X. Huang, C. Xu, W. Liu, D.Y.W. Yu, H.H. Hng, H.E. Hoster and Q. Yan, “Cu Doped V2O5 Flowers as Cathode Material for High-Performance Lithium Ion Batteries”, Nanoscale (2013) 5 (11), 4937-4943.
  39. D. Yang, J. Zhu, X. Rui, H. Tan, R. Cai, H.E. Hoster, D.Y.W. Yu, H.H. Hng and Q. Yan, “Synthesis of Cobalt Phosphides and Their Application as Anodes for Lithium Ion Batteries”, ACS Appl. Mater. Interfaces (2013) 5, 1093-1099.
  40. C. W. Mason, I. Gocheva, H. Hoster, D.Y.W. Yu, “Activating vanadium’s highest oxidation state in the NASICON structure”, ECS Transactions (2013)58, 41-46.
  41. Y. Luo, J. Luo, W. Zhou, X. Qi, H. Zhang, D.Y.W. Yu, C.M. Li, H.J. Fan and T. Yu, “Controlled synthesis of hierarchical graphene-wrapped TiO2@Co3O4 coaxial nanobelt arrays for high-performance lithium storage”, J. Mater. Chem. A (2013) 1, 273-281.
  42. W. Zhou, Y.Y. Tay, X. Jia, D.Y.W. Yu, J. Jiang, H.H. Hng and T. Yu, “Controlled Growth of SnO2@Fe2O3 Double-sided Nanocombs as Anodes for Lithium-ion Batteries”, Nanoscale (2012) 4, 4459-4463.
  43. P. V. Prikhodchenko, J. Gun, S. Sladkevich, A. A. Mikhaylov, O. Lev, Y. Y. Tay, S. K. Batabyal and D.Y.W. Yu*, “Conversion of Hydroperoxoantimonate Coated Graphenes to Sb2S3@Graphene for a Superior Lithium Battery Anode”, Chem. Mater. (2012) 24, 4750-4757.
  44. D.Y.W. Yu*, Y. Reynier, J. Dodd Cardema, Y. Ozawa and R. Yazami, “Thermodynamic Study of Lithium-ion Battery Materials”, MRS Proceedings (2012) 1388.
  45. Y. Luo, J. Jiang, W. Zhou, H. Yang, J. Jiang, X. Qi, H. Zhang, D.Y.W. Yu, C.M. Li and T. Yu, “Self-assembly of Well-ordered Whisker-like Manganese Oxide Arrays on Carbon Fiber Paper and Its Application as Electrode Material for Supercapacitors”, J. Mater. Chem. (2012) 22, 8634.
  46. Y. Luo, J. Luo, J. Jiang, W. Zhou, H. Yang, X. Qi, H. Zhang, H. Fan, D.Y.W. Yu, C.M. Li and T. Yu, “Seed-Assisted Synthesis of Highly Ordered TiO2@a-Fe2O3 Core/Shell Arrays on Carbon Textiles for Lithium-ion Battery Applications”, Energy Environ. Sci. (2012) 5, 6559. 
  47. Y. Zeng, W. Zhang, C. Xu, N. Xiao, D.Y.W. Yu, Y. Huang, H.H. Hng and Q. Yan, “One-Step Solvothermal Synthesis of Single Crystalline TiOF2 Nanotubes with High Lithium-ion Battery Performance”, Chemistry – A Eur. J.(2012) 18, 4026.
  48. D.Y.W. Yu* and K. Yanagida, “Structural Analysis of Li2MnO3 and Related Li-Mn-O Materials”, J. Electrochem. Soc. (2011) 158, A1015.
  49. D.Y.W. Yu*, K. Yanagida and H. Nakamura, “Surface modification of Li-excess Mn-based cathode materials”, J. Electrochem. Soc. (2010) 157, A1177.
  50. D.Y.W. Yu*, K. Yanagida, Y. Kato and H. Nakamura, “Electrochemical activities in Li2MnO3”, J. Electrochem. Soc. (2009)156, A417.
  51. D.Y.W. Yu*, K. Donoue, T. Kadohata, T. Murata, S. Matsuta and S. Fujitani, “Impurities in LiFePO4 and their influence on material characteristics”, J. Electrochem. Soc. (2008) 155, A526.
  52. D.Y.W. Yu*, C. Fietzek, W. Weydanz, K. Donoue, T. Inoue, H. Kurokawa and S. Fujitani, “Study of LiFePO4 by cyclic voltammetry”, J. Electrochem. Soc. (2007) 154, A253.
  53. D.Y.W. Yu*, K. Donoue, T. Inoue, M. Fujimoto and S. Fujitani, "Effect of electrode parameters on LiFePO4 cathodes", J. Electrochem. Soc. (2006) 153, A835.