Teklay Mezgebe Hagos
@ntust.edu.tw
Chemical Engineering
National Taiwan University of Science and Technology
RESEARCH, TEACHING, or OTHER INTERESTS
Electrochemistry, Renewable Energy, Sustainability and the Environment, Energy Engineering and Power Technology, Chemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Yosef Nikodimos, Shi-Kai Jiang, Shing-Jong Huang, Bereket Woldegbreal Taklu, Wei-Hsiang Huang, Gidey Bahre Desta, Teshager Mekonnen Tekaligne, Zabish Bilew Muche, Keseven Lakshmanan, Chia-Yu Chang,et al.
American Chemical Society (ACS)
Bereket Woldegbreal Taklu, Wei-Nien Su, Jeng-Chian Chiou, Chia-Yu Chang, Yosef Nikodimos, Keseven Lakshmanan, Teklay Mezgebe Hagos, Gashahun Gobena Serbessa, Gidey Bahre Desta, Teshager Mekonnen Tekaligne,et al.
American Chemical Society (ACS)
The use of the “Holy Grail” lithium metal anode is pivotal to achieve superior energy density. However, the practice of a lithium metal anode faces practical challenges due to the thermodynamic instability of lithium metal and dendrite growth. Herein, an artificial stabilization of lithium metal was carried out via the thermal pyrolysis of the NH4F salt, which generates HF(g) and NH3(g). An exposure of lithium metal to the generated gas induces a spontaneous reaction that forms multiple solid electrolyte interface (SEI) components, such as LiF, Li3N, Li2NH, LiNH2, and LiH, from a single salt. The artificially multilayered protection on lithium metal (AF-Li) sustains stable lithium stripping/plating. It suppresses the Li dendrite under the Li||Li symmetric cell. The half-cell Li||Cu and Li||MCMB systems depicted the attributions of the protective layer. We demonstrate that the desirable protective layer in AF-Li exhibited remarkable capacity retention (CR) results. LiFePO4 (LFP) showed a CR of 90.6% at 0.5 mA cm–2 after 280 cycles, and LiNi0.5Mn0.3Co0.2O2 (NCM523) showed 58.7% at 3 mA cm–2 after 410 cycles. Formulating the multilayered protection, with the simultaneous formation of multiple SEI components in a facile and cost-effective approach from NH4F as a single salt, made the system competent.
Endalkachew Asefa Moges, Chia-Yu Chang, Wei-Hsiang Huang, Fikiru Temesgen Angerasa, Keseven Lakshmanan, Teklay Mezgebe Hagos, Habib Gemechu Edao, Woldesenbet Bafe Dilebo, Chi-Wen Pao, Meng-Che Tsai,et al.
American Chemical Society (ACS)
Currently, hydrogen peroxide (H2O2) manufacturing involves an energy-intensive anthraquinone technique that demands expensive solvent extraction and a multistep process with substantial energy consumption. In this work, we synthesized Pd-N4-CO, Pd-S4-NCO, and Pd-N2O2-C single-atom catalysts via an in situ synthesis approach involving heteroatom-rich ligands and activated carbon under mild reaction conditions. It reveals that palladium atoms interact strongly with heteroatom-rich ligands, which provide well-defined and uniform active sites for oxygen (O2) electrochemically reduced to hydrogen peroxide. Interestingly, the Pd-N4-CO electrocatalyst shows excellent performance for the electrocatalytic reduction of O2 to H2O2 via a two-electron transfer process in a base electrolyte, exhibiting a negligible amount of onset overpotential and >95% selectivity within a wide range of applied potentials. The electrocatalysts based on the activity and selectivity toward 2e- ORR follow the order Pd-N4-CO > Pd-N2O2-C > Pd-S4-NCO in agreement with the pull-push mechanism, which is the Pd center strongly coordinated with high electronegativity donor atoms (N and O atoms) and weakly coordinated with the intermediate *OOH to excellent selectivity and sustainable production of H2O2. According to density functional theory, Pd-N4 is the active site for selectivity toward H2O2 generation. This work provides an emerging technique for designing high-performance H2O2 electrosynthesis catalysts and the rational integration of several active sites for green and sustainable chemical synthesis via electrochemical processes.
Yosef Nikodimos, Wei-Nien Su, Kassie Nigus Shitaw, Shi-Kai Jiang, Ljalem Hadush Abrha, Misganaw Adigo Weret, Semaw Kebede Merso, Teklay Mezgebe Hagos, Chen-Jui Huang, Keseven Lakshmanan,et al.
Elsevier BV
Bereket Woldegbreal Taklu, Yosef Nikodimos, Hailemariam Kassa Bezabh, Keseven Lakshmanan, Teklay Mezgebe Hagos, Teshome Assefa Nigatu, Semaw Kebede Merso, Hung-Yi Sung, Sheng-Chiang Yang, She-Huang Wu,et al.
Elsevier BV
Gebregziabher Brhane Berhe, Wei-Nien Su, Tesfaye Teka Hagos, Hailemariam Kassa Bezabh, Teklay Mezgebe Hagos, and Bing Joe Hwang
Elsevier BV
Hailemariam Kassa Bezabh, Jeng-Chian Chiou, Teshome Assefa Nigatu, Teklay Mezgebe Hagos, Shi-Kai Jiang, Yosef Nikodimos, Bereket Woldegbreal Taklu, Meng-Che Tsai, Wei-Nien Su, and Bing Joe Hwang
American Chemical Society (ACS)
Electrochemical stability and interfacial reactions are crucial for rechargeable aqueous zinc batteries. Electrolyte engineering with low-cost aqueous electrolytes is highly required to stabilize their interfacial reactions. Herein, we propose a design strategy using glutamic additive and its derivatives with modification of hydrogen-bonding network to enable Zn aqueous battery at a low concentration (2 m ZnSO4 + 1 m Li2SO4). Computational, in situ/ex situ spectroscopic, and electrochemical studies suggest that additives with moderate interactions, such as 0.1 mol % glutamic additive (G1), preferentially absorb on the Zn surface to homogenize Zn2+ plating and favorably interact with Zn2+ in bulk to weaken the interaction between H2O and Zn2+. As a result, uniform deposition and stable electrochemical performance are realized. The Zn||Cu half-cell lasts for more than 200 cycles with an average Coulombic efficiency (CE) of >99.32% and the Zn||Zn symmetrical cells for 1400 h with a low and stable overpotential under a current density of 0.5 mA cm-2, which is better than the reported results. Moreover, adding 0.1 mol % G1 to the Zn||LFP full cell improves its electrochemical performance with stable cycling and achieves a remarkable capacity of 147.25 mAh g-1 with a CE of 99.79% after 200 cycles.
Haylay Ghidey Redda, Yosef Nikodimos, Wei-Nien Su, Ruei-San Chen, Teklay Mezgebe Hagos, Hailemariam Kassa Bezabh, Haile Hisho Weldeyohannes, and Bing Joe Hwang
Elsevier BV
Boas Tua Hotasi, Teklay Mezgebe Hagos, Chen Jui Huang, Shi-Kai Jiang, Bikila Alemu Jote, Kassie Nigus Shitaw, Hailemariam Kassa Bezabh, Chia-Hsin Wang, Wei-Nien Su, She-Huang Wu,et al.
Elsevier BV
Yosef Nikodimos, Wei-Nien Su, Bereket Woldegbreal Taklu, Semaw Kebede Merso, Teklay Mezgebe Hagos, Chen-Jui Huang, Haylay Ghidey Redda, Chia-Hsin Wang, She-Huang Wu, Chun-Chen Yang,et al.
Elsevier BV
Teklay Mezgebe Hagos, Hailemariam Kassa Bezabh, Chen-Jui Huang, Shi-Kai Jiang, Wei-Nien Su, and Bing Joe Hwang
American Chemical Society (ACS)
ConspectusLithium (Li) metal is the ultimate negative electrode due to its high theoretical specific capacity and low negative electrochemical potential. However, the handling of lithium metal imposes safety concerns in transportation and production due to its reactive nature. Recently, anode-free lithium metal batteries (AFLMBs) have drawn much attention because of several of their advantages, including higher energy density, lower cost, and fewer safety concerns during cell production compared to LMBs. Pushing the reversible Coulombic efficiency (CE) of AFLMBs up to 99.98% is key to achieving their 80% capacity retention over more than 1000 cycles. However, interfacial irreversible phenomena such as electrolyte decomposition reactions on both electrodes, dead Li formation, and Li dendrite formation result in poor capacity retention and short circuits in LMBs and AFLMBs. Therefore, it is of great importance and scientific interest to explore those interfacial irreversible phenomena to improve the cell's cycle life. Although significant contributions toward mitigating electrolyte decomposition, dead lithium, and dendritic lithium formation have been reported at the lithium anode, real irreversible phenomena are usually hidden or difficult to discover due to excess lithium employed in LMBs and simultaneous events taking place in both electrodes or at the interfaces.An integrated protocol is suggested to include Li||Cu, cathode||Li, and cathode||Cu configurations to provide overall quantification and determination of various sources of irreversible Coulombic efficiency (irr-CE) in AFLMBs and LMBs. Combining Li||Cu, cathode||Li, and cathode||Cu configurations is essential for separating the root sources of the capacity loss and irr-CE in LMBs and AFLMBs. Remarkably, integrating an anode-free cell with various analytical techniques can serve as a powerful protocol to decouple and quantify those interfacial irreversible phenomena according to our recent reports.In this Account, we focus on the protocol based on an anode-free cell combined with various analytical methods to investigate interfacial irreversible phenomena. Complementary advanced tools such as transmission X-ray microscopy (visualizing Li plating/stripping mechanism), nuclear magnetic resonance spectroscopy (quantifying dead lithium), and gas chromatography-mass spectroscopy (decoupling interfacial reactions) were employed to extract the intrinsic reasons and sources of individual irreversible reactions in LMBs and AFLMBs. Quantitative evaluation of nucleation and growth of Li metal deposition are addressed, along with solid electrolyte interphase (SEI) fracture, visualization of lithium dendrite growth, decoupling of oxidative and reductive electrolyte decomposition mechanisms, and irreversible efficiency (i.e., dead Li and SEI formation) to reveal the intrinsic causes of individual irr-CE in AFLMBs. Meanwhile, an anode-free protocol can also be utilized as a powerful and multifunctional tool to develop electrolyte formulations or artificial layers for LMBs and AFLMBs. Therefore, we also suggest that the anode-free configurations with significant irreversible phenomena can effectively screen and develop new electrolytes. Finally, the concepts of the protocol with an anode-free cell combined with various advanced analytical tools can be extended to provide an in-depth understanding of other metal batteries and solid-state anode-free metal batteries.
Teklay Mezgebe Hagos, Hailemariam Kassa Bezabh, Haylay Ghidey Redda, Endalkachew Asefa Moges, Wei-Hsiang Huang, Chen-Jui Huang, Wei-Nien Su, Hongjie Dai, and Bing Joe Hwang
Elsevier BV
Haile Hisho Weldeyohannes, Ljalem Hadush Abrha, Yosef Nikodimos, Kassie Nigus Shitaw, Teklay Mezgebe Hagos, Chen-Jui Huang, Chia-Hsin Wang, She-Huang Wu, Wei-Nien Su, and Bing Joe Hwang
Elsevier BV
Hailemariam Kassa Bezabh, Shuo-Feng Chiu, Teklay Mezgebe Hagos, Meng-Che Tsai, Yosef Nikodimos, Haylay Ghidey Redda, Wei-Nien Su, and Bing Joe Hwang
Elsevier BV
Haylay Ghidey Redda, Yosef Nikodimos, Wei-Nien Su, Ruei-San Chen, Shi-Kai Jiang, Ljalem Hadush Abrha, Teklay Mezgebe Hagos, Hailemariam Kassa Bezabh, Haile Hisho Weldeyohannes, and Bing Joe Hwang
Elsevier BV
Teklay Mezgebe Hagos, Tesfaye Teka Hagos, Hailemariam Kassa Bezabh, Gebregziabher Brhane Berhe, Ljalem Hadush Abrha, Shuo-Feng Chiu, Chen-Jui Huang, Wei-Nien Su, Hongjie Dai, and Bing Joe Hwang
American Chemical Society (ACS)
The anode-free full cell architecture (Cu||NMC111) is an essential milestone for boosting the energy density of lithium metal batteries (LMBs). The LiPF6 dissolved in fluorinated carbonate (fluoroe...
Gebregziabher Brhane Berhe, Wei-Nien Su, Ljalem Hadush Abrha, Hailemariam Kassa Bezabh, Teklay Mezgebe Hagos, Tesfaye Teka Hagos, Chen-Jui Huang, Niguse Aweke Sahalie, Bikila Alemu Jote, Balamurugan Thirumalraj,et al.
Royal Society of Chemistry (RSC)
Composite film of polyvinylidene difluoride (PVDF) and Li5.6Ga0.26La2.9Zr1.87Nb0.05O12 garnet improves the cycling stability and rate capability of lithium manganese oxide (LMO) cathode.
Tesfaye Teka Hagos, Wei-Nien Su, Chen-Jui Huang, Balamurugan Thirumalraj, Shuo-Feng Chiu, Ljalem Hadush Abrha, Teklay Mezgebe Hagos, Hailemariam Kassa Bezabh, Gebregziabher Brhane Berhe, Wodaje Addis Tegegne,et al.
Elsevier BV
Ljalem Hadush Abrha, Tesfaye Teka Hagos, Yosef Nikodimos, Hailemariam Kassa Bezabh, Gebregziabher Brhane Berhe, Teklay Mezgebe Hagos, Chen-Jui Huang, Wodaje Addis Tegegne, Shi-Kai Jiang, Haile Hisho Weldeyohannes,et al.
American Chemical Society (ACS)
Li7La3Zr2O12 (LLZO) garnet is one kind of solid electrolytes drawing extensive attention due to their good ionic conductivity, safety and stability towards lithium metal anode. However, the stability problem during synthesis and storage results in high interfacial resistance and prevents them from practical applications. We synthesized air-stable dual-doped Li5.6La2.9Ga0.26Zr1.87Nb0.05O12 ((Ga, Nb)-LLZO) cubic phase garnet with ionic conductivity of 9.28 10-3 S cm-1. The impurity phase species formation on the garnet pellets after air exposure were investigated. LiOH and Li2CO3 can be observed on the garnet pellets by Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), once the garnets are exposed to humid air or in contact with water. The (Ga, Nb)-LLZO garnet is found to form less LiOH and Li2CO3 which can be further reduced or removed after drying treatment. To confirm the stability of the garnet, electrochemical test of Li//Li symmetric cell was also performed in comparison with previously reported garnet (Li6.9La2.6Ca0.22Zr1.82Nb0.25O12, (Ca, Nb)-LLZO). The dual-doped (Ga, Nb)-LLZO shows less polarized and stable plating/striping behavior than (Ca, Nb)-LLZO. Through Rietveld refinement of XRD patterns of prepared materials, dopant Ga is found to preferably occupy the Li site and Nb takes the Zr site, while dopant Ca mainly substitute La in the reference sample. The inherited properties of the dopants in (Ga, Nb)-LLZO and their structural synergy explain the greatly improved air stability and reduced interfacial resistance. This may open a new direction to realize garnet based solid electrolytes with lower interfacial resistance and superior air stability.
Hailemariam Kassa Bezabh, Meng-Che Tsai, Tesfaye Teka Hagos, Tamene Tadesse Beyene, Gebregziabher Brhane Berhe, Teklay Mezgebe Hagos, Ljalem Hadush Abrha, Shuo-Feng Chiu, Wei-Nien Su, and Bing Joe Hwang
Elsevier BV
Ljalem Hadush Abrha, Tilahun Awoke Zegeye, Tesfaye Teka Hagos, Hogiartha Sutiono, Teklay Mezgebe Hagos, Gebregziabher Brhane Berhe, Chen-Jui Huang, Shi-Kai Jiang, Wei-Nien Su, Yaw-Wen Yang,et al.
Elsevier BV
Gebregziabher Brhane Berhe, Wei-Nien Su, Chen-Jui Huang, Teklay Mezgebe Hagos, Tesfaye Teka Hagos, Hailemariam Kassa Bezabh, Misganaw Adigo Weret, Ljalem Hadush Abrha, Yaw-Wen Yang, and Bing-Joe Hwang
Elsevier BV
Teklay Mezgebe Hagos, Gebregziabher Brhane Berhe, Tesfaye Teka Hagos, Hailemariam Kassa Bezabh, Ljalem Hadush Abrha, Tamene Tadesse Beyene, Chen-Jui Huang, Yaw-Wen Yang, Wei-Nien Su, Hongjie Dai,et al.
Elsevier BV
Tesfaye Teka Hagos, Balamurugan Thirumalraj, Chen-Jui Huang, Ljalem Hadush Abrha, Teklay Mezgebe Hagos, Gebregziabher Brhane Berhe, Hailemariam Kassa Bezabh, Jim Cherng, Shuo-Feng Chiu, Wei-Nien Su,et al.
American Chemical Society (ACS)
Currently, concentrated electrolyte solutions are attracting special attention because of their unique characteristics such as unusually improved oxidative stability on both the cathode and anode sides, the absence of free solvent, the presence of more anion content, and the improved availability of Li+ ions. Most of the concentrated electrolytes reported are lithium bis(fluorosulfonyl)imide (LiFSI) salt with ether-based solvents because of the high solubility of salts in ether-based solvents. However, their poor anti-oxidation capability hindered their application especially with high potential cathode materials (>4.0 V). In addition, the salt is very costly, so it is not feasible from the cost analysis point of view. Therefore, here we report a locally concentrated electrolyte, 2 M LiPF6, in ethylene carbonate/diethyl carbonate (1:1 v/v ratio) diluted with fluoroethylene carbonate (FEC), which is stable within a wide potential range (2.5-4.5 V). It shows significant improvement in cycling stability of lithium with an average Coulombic efficiency (ACE) of ∼98% and small voltage hysteresis (∼30 mV) with a current density of 0.2 mA/cm2 for over 1066 h in Li||Cu cells. Furthermore, we ascertained the compatibility of the electrolyte for anode-free Li-metal batteries (AFLMBs) using Cu||LiNi1/3Mn1/3Co1/3O2 (NMC, ∼2 mA h/cm2) with a current density of 0.2 mA/cm2. It shows stable cyclic performance with ACE of 97.8 and 40% retention capacity at the 50th cycle, which is the best result reported for carbonate-based solvents with AFLMBs. However, the commercial carbonate-based electrolyte has <90% ACE and even cannot proceed more than 15 cycles with retention capacity >40%. The enhanced cycle life and well retained in capacity of the locally concentrated electrolyte is mainly because of the synergetic effect of FEC as the diluent to increase the ionic conductivity and form stable anion-derived solid electrolyte interphase. The locally concentrated electrolyte also shows high robustness to the effect of upper limit cutoff voltage.
Tamene Tadesse Beyene, Hailemariam Kassa Bezabh, Misganaw Adigo Weret, Teklay Mezgebe Hagos, Chen-Jui Huang, Chia-Hsin Wang, Wei-Nien Su, Hongjie Dai, and Bing-Joe Hwang
The Electrochemical Society