Engineering topics
Cui, Zhiming
Publications and source records attributed to Cui, Zhiming.
In Situ Formation of Li 3 P Layer Enables Fast Li + Conduction across Li/Solid Polymer Electrolyte Interface
Abstract Solid‐state polymer electrolytes provide better flexibility and electrode contact than their ceramic counterparts, making them a worthwhile pursuit for all‐solid‐state lithium‐metal batteries. However, their large Li/solid state electrolyte interfacial resistance, small critical current density, and rapid lithium dendrite growth during cycling still limit their viability. Owing to these restrictions, all‐solid‐state cells with solid polymer electrolytes must be cycled above room‐temperature and with a small current density. These problems can be mitigated with an in situ formed artificial solid electrolyte interphase that rapidly conducts Li + ions. Herein, a Li 3 P layer formed in situ at the Li‐metal/solid polymer electrolyte interphase is reported that significantly reduces the electrode/electrolyte interfacial resistance. Additionally, this layer increases the wettability of the solid polymer by the metallic lithium anode, allowing for the critical current density of lithium symmetric cells to be doubled by homogenizing the current density at the interface. All‐solid‐state Li/Li symmetric cells and Li/LiFePO 4 cells with the Li 3 P layer show improved cycling performance with a high current density.
Exceptional oxygen evolution reactivities on CaCoO 3 and SrCoO 3
We investigated the roles of covalent bonding, separation of surface oxygen, and electrolyte pH on the oxygen evolution reaction (OER) on transition metal oxides by comparing catalytic onset potentials and activities of CaCoO 3 and SrCoO 3 . Both cubic, metallic perovskites have similar Co IV intermediate spin states and onset potentials, but a substantially smaller lattice parameter and shorter surface oxygen separation make CaCoO 3 a more stable catalyst with increased OER activity. The onset potentials are similar, occurring where H + is removed from surface -OH - , but two competing surface reactions determine the catalytic activity. In one, the surface -O - is attacked by electrolyte OH - to form the surface -OOH - ; in the other, two -O - form a surface peroxide ion and an oxygen vacancy with electrolyte OH - attacking the oxygen vacancy. The second pathway can be faster if the surface oxygen separation is smaller.
Structurally Ordered Fe 3 Pt Nanoparticles on Robust Nitride Support as a High Performance Catalyst for the Oxygen Reduction Reaction
Abstract The commercialization of fuel cell technologies requires a significant reduction in the amount of expensive platinum catalyst in the cathode while still maintaining high catalytic activity and stability. Herein a cost‐effective, highly durable, and efficient catalyst consisting of ordered Fe 3 Pt nanoparticles supported by mesoporous Ti 0.5 Cr 0.5 N (Fe 3 Pt/Ti 0.5 Cr 0.5 N) is demonstrated. The Fe 3 Pt/Ti 0.5 Cr 0.5 N catalyst exhibits a five‐fold increase in mass activity relative to a Pt/C catalyst at 0.9 V for the oxygen reduction reaction. More importantly, the catalyst shows a minimal loss of activity after 5000 potential cycles (9.7%). The enhanced activity of the ordered Fe 3 Pt/Ti 0.5 Cr 0.5 N catalyst, in combination with its enhanced stability, makes it very promising for the development of new cathode catalysts for fuel cells.
Garnet Electrolyte with an Ultralow Interfacial Resistance for Li-Metal Batteries
Not provided.
Durable and Efficient Hollow Porous Oxide Spinel Microspheres for Oxygen Reduction
Abstract not provided
Ni 3 FeN‐Supported Fe 3 Pt Intermetallic Nanoalloy as a High‐Performance Bifunctional Catalyst for Metal–Air Batteries
Abstract Electrocatalysts for both the oxygen reduction and evolution reactions (ORR and OER) are vital for the performances of rechargeable metal–air batteries. Herein, we report an advanced bifunctional oxygen electrocatalyst consisting of porous metallic nickel‐iron nitride (Ni 3 FeN) supporting ordered Fe 3 Pt intermetallic nanoalloy. In this hybrid catalyst, the bimetallic nitride Ni 3 FeN mainly contributes to the high activity for the OER while the ordered Fe 3 Pt nanoalloy contributes to the excellent activity for the ORR. Robust Ni 3 FeN‐supported Fe 3 Pt catalysts show superior catalytic performance to the state‐of‐the‐art ORR catalyst (Pt/C) and OER catalyst (Ir/C). The Fe 3 Pt/Ni 3 FeN bifunctional catalyst enables Zn–air batteries to achieve a long‐term cycling performance of over 480 h at 10 mA cm −2 with high efficiency. The extraordinarily high performance of the Fe 3 Pt/Ni 3 FeN bifunctional catalyst makes it a very promising air cathode in alkaline electrolyte.
Ni 3 FeN-Supported Fe 3 Pt Intermetallic Nanoalloy as a High-Performance Bifunctional Catalyst for Metal-Air Batteries
Electrocatalysts for both the oxygen reduction and evolution reactions (ORR and OER) are vital for the performances of rechargeable metal–air batteries. Herein, we report an advanced bifunctional oxygen electrocatalyst consisting of porous metallic nickel-iron nitride (Ni 3 FeN) supporting ordered Fe 3 Pt intermetallic nanoalloy. In this hybrid catalyst, the bimetallic nitride Ni 3 FeN mainly contributes to the high activity for the OER while the ordered Fe 3 Pt nanoalloy contributes to the excellent activity for the ORR. Robust Ni 3 FeN-supported Fe 3 Pt catalysts show superior catalytic performance to the state-of-the-art ORR catalyst (Pt/C) and OER catalyst (Ir/C). The Fe 3 Pt/Ni 3 FeN bifunctional catalyst enables Zn–air batteries to achieve a long-term cycling performance of over 480 h at 10 mA cm –2 with high efficiency. We report the extraordinarily high performance of the Fe 3 Pt/Ni 3 FeN bifunctional catalyst makes it a very promising air cathode in alkaline electrolyte.
Na x MV(PO 4 ) 3 (M = Mn, Fe, Ni) Structure and Properties for Sodium Extraction
Explore the source record for details and available documents.
Mastering the interface for advanced all-solid-state lithium rechargeable batteries
Not Available
Ni 3 Fe-N Doped Carbon Sheets as a Bifunctional Electrocatalyst for Air Cathodes
A promising bifunctional electrocatalyst is reported for air cathodes consisting of Ni 3 Fe nanoparticles embedded in porous nitrogen–doped carbon sheets (Ni 3 Fe/N–C sheets) by a facile and effective pyrolysis–based route with sodium chloride (NaCl) crystals as a template. Here, the Ni 3 Fe/N–C sheets show excellent catalytic activity, selectivity, and durability toward both the oxygen–reduction and oxygen–evolution reactions (ORR and OER). They are shown to provide a superior, low–cost cathode for a rechargeable Zn–air battery. At a discharge–charge current density of 10 mA cm –2 , the Ni 3 Fe/N–C sheets enable a Zn–air battery to cycle steadily up to 420 h with only a small increase in the round–trip overpotential, outperforming the more costly Pt/C + IrO 2 mixture catalyst (160 h). With the simplicity and scalability of the synthetic approach and its remarkable bifunctional electrocatalytic performance, the Ni 3 Fe/N–C sheets offer a promising rechargeable air cathode operating at room temperature in an alkaline electrolyte.
Fluorine‐Doped Antiperovskite Electrolyte for All‐Solid‐State Lithium‐Ion Batteries
Abstract A fluorine‐doped antiperovskite Li‐ion conductor Li 2 (OH)X (X=Cl, Br) is shown to be a promising candidate for a solid electrolyte in an all‐solid‐state Li‐ion rechargeable battery. Substitution of F − for OH − transforms orthorhombic Li 2 OHCl to a room‐temperature cubic phase, which shows electrochemical stability to 9 V versus Li + /Li and two orders of magnitude higher Li‐ion conductivity than that of orthorhombic Li 2 OHCl. An all‐solid‐state Li/LiFePO 4 with F‐doped Li 2 OHCl as the solid electrolyte showed good cyclability and a high coulombic efficiency over 40 charge/discharge cycles.
Fluorine-doped antiperovskite electrolyte for all-solid-state Lithium-ion batteries
A fluorine-doped antiperovskite Li-ion conducto Li 2 (OH)X (X=Cl, Br) is shown to be a promising candidat for a solid electrolyte in an all-solid-state Li-ion rechargeabl battery. Substitution of F¯ for OH¯ transforms orthorhombi Li 2 OHCl to a room-temperature cubic phase, which show electrochemical stability to 9 V versus Li + /Li and two orders o magnitude higher Li-ion conductivity than that of orthorhombi Li 2 OHCl. As a result, an all-solid-state Li/LiFePO 4 with F-dope Li 2 OHCl as the solid electrolyte showed good cyclability an a high coulombic efficiency over 40 charge/discharge cycles
High-Performance Pd 3 Pb Intermetallic Catalyst for Electrochemical Oxygen Reduction
Extensive efforts to develop highly active and strongly durable electrocatalyst for oxygen reduction are motivated by a need for metal–air batteries and fuel cells. In this work, we report a very promising catalyst prototype of structurally ordered Pd-based alloys, Pd 3 Pb intermetallic compound. Such structurally ordered Pd 3 Pb/C exhibits a significant increase in mass activity. More importantly, compared to the conventional Pt/C catalysts, ordered Pd 3 Pb/C is highly durable and exhibits a much longer cycle life and higher cell efficiency in Zn-air batteries. Interestingly, ordered Pd 3 Pb/C possesses very high methanol tolerance during electrochemical oxygen reduction, which make it an excellent methanol-tolerant cathode catalyst for alkaline polymer electrolyte membrane fuel cells. Here, we offer a promising route to optimize the synthesis of ordered Pd-based intermetallic catalysts for fuel cells and metal-air batteries.
Structurally Ordered Pt 3 Cr as Oxygen Reduction Electrocatalyst: Ordering Control and Origin of Enhanced Stability
Explore the source record for details and available documents.