ORCID Profile
0000-0001-8687-8946
Current Organisation
The Hong Kong Polytechnic University
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Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM15048D
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2EE23145J
Publisher: Elsevier BV
Date: 10-2013
Publisher: Wiley
Date: 08-04-2014
Abstract: Nanocomposites that contain reinforcements with preferred orientation have attracted significant attention because of their promising applications in a wide range of multifunctional fields. Many efforts have recently been focused on developing facile methods for preparing aligned graphene sheets in solvents and polymers because of their fascinating properties including liquid crystallinity and highly anisotropic characteristics. Self-aligned in situ reduced graphene oxide (rGO) olymer nanocomposites are prepared using an all aqueous casting method. A remarkably low percolation threshold of 0.12 vol% is achieved in the rGO/epoxy system owing to the uniformly dispersed, monolayer graphene sheets with extremely high aspect ratios (>30000). The self-alignment into a layered structure at above a critical filler content induces a unique anisotropy in electrical and mechanical properties due to the preferential formation of conductive and reinforcing networks along the alignment direction. Accompanied by the anisotropic electrical conductivities are exceptionally high dielectric constants of over 14000 with 3 wt% of rGO at 1 kHz due to the charge accumulation at the highly-aligned conductive filler/insulating polymer interface according to the Maxwell-Wagner-Sillars polarization principle. The highly dielectric rGO/epoxy nanocomposites with the engineered structure and properties present high performance electromagnetic interference shielding with a remarkable shilding efficiency of 38 dB.
Publisher: Wiley
Date: 17-01-2022
Abstract: The mechanical properties of the solid electrolyte interphase (SEI) have attracted increasing attention, but their importance in guiding electrolyte design remains ambiguous. Here it is revealed that, despite a decrease in ionic conductivity for both electrolyte and SEI, exceptional cycling performance of K‐metal batteries is achieved in a low concentration carbonate electrolyte by optimizing the mechanical stability of the SEI. The SEI formed in the studied carbonate electrolytes is predominantly organic. Its inorganic content increases with increasing electrolyte concentration and corresponds to an increase in Young's modulus ( E ) and ionic conductivity of SEI and a decrease in elastic strain limit (ε Y ). The maximum elastic deformation energy combines effects of E and ε Y , achieving a maximum in 0.5 m electrolyte. Finite element simulations indicate that SEI with low either E or ε Y inevitably triggers dendrite growth. These findings foreshadow an increased focus on the mechanical properties of the SEI, where low concentrations of carbonate electrolytes display merit.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM33615D
Publisher: Elsevier BV
Date: 07-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM33960A
Publisher: American Chemical Society (ACS)
Date: 09-06-2015
Abstract: A facile electrospinning method with subsequent heat treatments is employed to prepare carbon nanofibers (CNFs) containing uniformly dispersed Co3O4 nanoparticles as electrodes for supercapacitors. The Co3O4/CNF electrodes with ∼68 wt % active particles deliver a remarkable capacitance of 586 F g(-1) at a current density of 1 A g(-1). When the current density is increased to 50 A g(-1), ∼66% of the original capacitance is retained. The electrodes also present excellent cyclic stability of 74% capacity retention after 2000 cycles at 2 A g(-1). These superior electrochemical properties are attributed to the uniform dispersion of active particles in the CNF matrix, which functions as a conductive support. The onionlike graphitic layers formed around the Co3O4 nanoparticles not only improve the electrical conductivity of the electrode but also prevent the separation of the nanoparticles from the carbon matrix.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 03-2016
Publisher: Elsevier BV
Date: 03-2014
Publisher: Wiley
Date: 28-07-2023
Abstract: Hydrogel electrolytes are widely explored in Zn metal batteries for application in wearable electronics. While extensive studies have been conducted on optimizing the chemical structure and boosting the tensile elasticity, the mechanical stability of the hydrogel under repeated deformation is largely overlooked, leading to unsatisfactory performance at large cycling capacity. This work systematically analyzes the compressive fatigue‐resistance properties of the hydrogel electrolyte, revealing the critical roles of the salt and copolymer matrix on crack initiation and propagation. It shows that, on the premise of homogeneous Zn deposition, an improved anti‐fatigue property is essential to achieve high‐capacity Zn metal anodes. The optimal Zn(ClO 4 ) 2 ‐polyacrylamide/chitosan hydrogel electrolyte (C‐PAMCS) exhibits an unprecedented lifespan of 1500 h for Zn//Zn cells at a current density of 10 mA cm −2 and a high areal capacity of 10 mAh cm −2 . The potential application of C‐PAMCS is exemplified in all‐flexible Zn‐ion batteries enabled by a flexible current collector consisting of a Ag nanowires embedded elastomer. This study provides the rationale under hydrogel electrolyte engineering toward advanced Zn‐ion battereis and the application in flexible devices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TA00426G
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 09-2012
Publisher: Wiley
Date: 21-12-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TA00507D
Publisher: Wiley
Date: 31-05-2023
Abstract: Ether electrolytes are promising for lithium metal batteries. Despite the intensive research in recent years, most state‐of‐the‐art ether electrolytes still cannot form reliable electrode‐electrolyte interfaces in NCM811‐Li batteries at diluted concentrations, especially in those operating at elevated temperatures. We report a simple but effective strategy to break this bottleneck and stabilize interfaces in high‐temperature NCM811‐Li batteries in ether electrolytes. We propose that by gradually extending the terminal groups of glycol diethers from methyl groups to n ‐butyl groups, the comprehensive stability of ether electrolytes is improved. An anion‐dominated solvation structure is realized at a concentration of 1 M. Accordingly, the electrode‐electrolyte interactions are suppressed, and a thinner, denser, and more inorganic‐rich solid‐ /cathode‐electrolyte interface is achieved. Additionally, the surface phase transition and structural degradation of NCM811 cathode are alleviated. Consequently, in the ethylene glycol dibutyl ether‐based electrolyte, the Coulombic efficiency for Li−Cu cells working at 60 °C is boosted to 99.41 % with a cycling life of over 200 cycles. The lifespan of high‐temperature NCM811‐Li cells is prolonged by more than 400 % with a stable average Coulombic efficiency of 99.77 % at quasi‐practical conditions of 50 μm Li, lean electrolyte of 10 μL mAh −1 , and medium‐high cathode loading of .2 mAh cm −2 .
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TA02916C
Abstract: Cobalt carbonate hydroxide/graphene aerogel and cobalt carbonate/graphene aerogel (CCH/GA and CC/GA) composites are synthesized as supercapacitor electrodes via a one-pot hydrothermal method.
Publisher: Springer Science and Business Media LLC
Date: 09-12-2019
DOI: 10.1007/S11239-019-02013-6
Abstract: The use of intramuscular injections is widely recommended to be avoided in patients who are prescribed anticoagulant agents, both oral and parenteral due to concerns of haematoma. Benzathine penicillin G (BPG), administered via intramuscular injection, is a vital treatment component for patients with rheumatic heart disease. BPG must be administered long term (for at least a decade) as part of treatment and alternative options to intramuscular injection are currently limited. Many of these patients with rheumatic heart disease will also require long term or lifelong anticoagulation. Our retrospective, single centre study of 48 adult and paediatric hospitalised patients, 29 of which were receiving concomitant anticoagulants, demonstrates no significant bleeding complications from intramuscular administration of BPG on the day of intramuscular injection and for 7 days post injection or until hospital discharge. In the absence of practical alternatives for patients with rheumatic heart disease, our local data supports continuing intramuscular injection of BPG in patients with rheumatic heart disease receiving anticoagulant medication.Letter to the editor.
Publisher: American Chemical Society (ACS)
Date: 21-01-2022
Publisher: Wiley
Date: 14-07-2015
Publisher: Wiley
Date: 15-11-2022
Abstract: The development of rechargeable Ca metal batteries (RCMBs) is hindered by the Ca 2+ passivating solid electrolyte interphases (SEIs). The cation solvation structure dictated by electrolyte chemistry plays a critical role in the SEIs properties. While a relatively weak cation‐solvent binding is preferred in Li metal anodes to promote anion‐derived SEIs, we demonstrate an enhanced Ca deposition/stripping reversibility under a strong cation‐solvent interaction, which is materialized in strongly‐solvating solvent and highly‐dissociated salt combinations. Such electrolyte formulations benefit the formation of solvent‐occupied solvation structure and minimize the anion reduction, resulting in organic‐rich/CaF 2 ‐poor SEIs for reversible Ca metal anodes. Furthermore, RCMBs paired with an organic cathode using the optimized electrolytes are demonstrated as a proof‐of‐concept. Our work reveals the paradigm shift in SEIs design for Ca metal anodes, opening up new opportunities for emerging RCMBs.
Publisher: Wiley
Date: 07-04-2023
Abstract: The cycling stability of batteries is closely related to the dynamic evolution of solid electrolyte interphases (SEIs) in response to the discharging/charging processes. Here, the state‐of‐the‐art cryogenic transmission electron microscopy (cryo‐TEM) and spectroscopy are utilized to probe the SEI breathing behavior induced by discharging/charging on the conversion‐type anode made of Fe 2 O 3 quasi‐cubes. The incorporation of the identical‐location strategy allows the tracking of the evolution of the same SEIs at different charge states. SEI breathing is shown to involve swelling (contracting) upon lithiation (de‐lithiation) driven by the reversible compositional change. Bare Fe 2 O 3 anodes develop an unstable SEI layer due to the intermixing with the lithiation product Li 2 O, which exhibits a large thickness variation upon breathing as well as excessive growth. A transition from organic to inorganic‐type SEI is also identified upon cycling, which gives rise to significantly increased SEI resistance. To tailor the SEI behavior, N‐doped carbon coating is applied on Fe 2 O 3 (Fe 2 O 3 @CN), which can effectively separate the lithiation product from SEI. A thinner and chemically more stable SEI layer develops on Fe 2 O 3 @CN, resulting in remarkably enhanced cycling stability compared to bare Fe 2 O 3 . This work demonstrates the importance of understanding and optimizing the dynamic behavior of SEIs to achieve better battery performance.
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0NH00517G
Abstract: The phase transformation of MoS 2 upon Li, Na, and K ion insertion is systematically explored. The exceptional stability associated with K ion uptake is revealed through complementary experimental and theoretical studies.
Publisher: Elsevier BV
Date: 06-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM34870E
Publisher: Elsevier BV
Date: 05-2014
Publisher: Elsevier BV
Date: 11-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TA04257C
Abstract: Multi-functionalized carbon nanofibers containing nanocavity-engineered Si particles as durable high-rate Li-ion anodes were fabricated via a facile electrospinning method.
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM31308A
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 12-2011
Publisher: American Chemical Society (ACS)
Date: 28-10-2014
DOI: 10.1021/AM504851S
Abstract: Nanocomposites consisting of ultrafine, cobalt carbonate nanoneedles and 3D porous graphene aerogel (CoCO3/GA) are in situ synthesized based on a one-step hydrothermal route followed by freeze-drying. A further heat treatment produces cobalt oxide nanoparticles embedded in the conductive GA matrix (Co(3)O(4)/GA). Both the composite anodes deliver excellent specific capacities depending on current density employed: the CoCO(3)/GA anode outperforms the Co(3)O(4)/GA anode at low current densities, and vice versa at current densities higher than 500 mA g(-1). Their electrochemical performances are considered among the best of similar composite anodes consisting of CoCO(3) or Co(3)O(4) active particles embedded in a graphene substrate. The stable multistep electrochemical reactions of the carbonate compound with a unique nanoneedle structure contribute to the excellent cyclic stability of the CoCO(3)/GA electrode, whereas the highly conductive networks along with low charge transfer resistance are responsible for the high rate performance of the Co(3)O(4)/GA electrode.
Publisher: Elsevier BV
Date: 11-2011
Publisher: Wiley
Date: 31-05-2023
Abstract: Ether electrolytes are promising for lithium metal batteries. Despite the intensive research in recent years, most state‐of‐the‐art ether electrolytes still cannot form reliable electrode‐electrolyte interfaces in NCM811‐Li batteries at diluted concentrations, especially in those operating at elevated temperatures. We report a simple but effective strategy to break this bottleneck and stabilize interfaces in high‐temperature NCM811‐Li batteries in ether electrolytes. We propose that by gradually extending the terminal groups of glycol diethers from methyl groups to n ‐butyl groups, the comprehensive stability of ether electrolytes is improved. An anion‐dominated solvation structure is realized at a concentration of 1 M. Accordingly, the electrode‐electrolyte interactions are suppressed, and a thinner, denser, and more inorganic‐rich solid‐ /cathode‐electrolyte interface is achieved. Additionally, the surface phase transition and structural degradation of NCM811 cathode are alleviated. Consequently, in the ethylene glycol dibutyl ether‐based electrolyte, the Coulombic efficiency for Li−Cu cells working at 60 °C is boosted to 99.41 % with a cycling life of over 200 cycles. The lifespan of high‐temperature NCM811‐Li cells is prolonged by more than 400 % with a stable average Coulombic efficiency of 99.77 % at quasi‐practical conditions of 50 μm Li, lean electrolyte of 10 μL mAh −1 , and medium‐high cathode loading of .2 mAh cm −2 .
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8EE03632B
Abstract: An optimized solid electrolyte interphase is the key to stabilization of microparticle anodes.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 2019
Abstract: Rechargeable aqueous zinc ion batteries (ZIBs) are considered as one of the most promising systems for large-scale energy storage due to their merits of low cost, environmental friendliness, and high safety. The utilization of aqueous electrolyte also brings about some problems such as low energy density, fast self-discharge, and capacity fading associated with the dissolution of metals in water. To combat the issues, we utilize a freestanding vanadium oxide hydrate/carbon nanotube (V 2 O 5 ·nH 2 O/CNT) film as the cathode and probe the performance in aqueous/organic hybrid electrolytes. The corresponding structural and morphological evolution of both V 2 O 5 ·nH 2 O/CNT cathode and Zn anode in different electrolytes is explored. The integrity of electrodes and the suppression of zinc dendrites during cycles are largely improved in the hybrid electrolytes. Accordingly, the battery in hybrid electrolyte exhibits high capacities of 549 mAh g -1 at 0.5 A g -1 after 100 cycles and 282 mAh g -1 at 4 A g -1 after 1000 cycles, demonstrating an excellent energy density of 102 Wh kg -1 at a high power of 1500 W kg -1 based on the cathode.
Publisher: Elsevier BV
Date: 08-1973
Publisher: American Chemical Society (ACS)
Date: 04-10-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TA03206C
Abstract: This paper reports a facile route to synthesize porous carbon nanofibers containing cobalt and cobalt oxide nanoparticles (CoO x /PCNF) as anodes for Li-ion batteries.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1JM00059D
Location: Hong Kong
No related grants have been discovered for Biao Zhang.