Electrochemical reduction of water to hydrogen(H2) offers a promising strategy for production of clean energy,but the design and optimization of electrochemical apparatus present challenges in terms of H2 recovery and...Electrochemical reduction of water to hydrogen(H2) offers a promising strategy for production of clean energy,but the design and optimization of electrochemical apparatus present challenges in terms of H2 recovery and energy consumption.Using cobalt phosphide nanoarrays(Co2 P/CoP NAs) as a charge mediator,we effectively separated the H2 and O2 evolution of alkaline water electrolysis in time,thereby achieving a membrane-free pathway for H2 purification.The hierarchical array structure and synergistic optimization of the electronic configuration of metallic Co2 P and metalloid CoP make the Co2 P/CoP NAs high-efficiency bifunctional electrocatalysts for both charge storage and hydrogen evolution.Theoretical investigations revealed that the introduction of Co2 P into CoP leads to a moderate hydrogen adsorption free energy and low water dissociation barrier,which are beneficial for boosting HER activity.Meanwhile,Co2 P/CoP NAs with high capacitance could maintain a cathodic H2 evolution time of 1500 s at 10 mA cm^(-2) driven by a low average voltage of 1.38 V.Alternatively,the energy stored in the mediator could be exhausted via coupling with the anodic oxidation of ammonia,whereby only 0.21 V was required to hold the current for 1188 s.This membrane-free architecture demonstrates the potential for developing hydrogen purification technology at low cost.展开更多
As the world works to move away from traditional energy sources,effective efficient energy storage devices have become a key factor for success.The emergence of unconventional electrochemical energy storage devices,in...As the world works to move away from traditional energy sources,effective efficient energy storage devices have become a key factor for success.The emergence of unconventional electrochemical energy storage devices,including hybrid batteries,hybrid redox flow cells and bacterial batteries,is part of the solution.These alternative electrochemical cell configurations provide materials and operating condition flexibility while offering high-energy conversion efficiency and modularity of design-to-design devices.The power of these diverse devices ranges from a few milliwatts to several megawatts.Manufactur-ing durable electronic and point-of-care devices is possible due to the development of all-solid-state batteries with efficient electrodes for long cycling and high energy density.New batteries made of earth-abundant metal ions are approaching the capacity of lithium-ion batteries.Costs are being reduced with the advent of flow batteries with engineered redox molecules for high energy density and membrane-free power generating electrochemical cells,which utilize liquid dynamics and interfaces(solid,liquid,and gaseous)for electrolyte separation.These batteries support electrode regeneration strategies for chemical and bio-batteries reducing battery energy costs.Other batteries have different benefits,e.g.,carbon-neutral Li-CO_(2) batteries consume CO_(2) and generate power,offering dual-purpose energy storage and carbon sequestration.This work considers the recent technological advances of energy storage devices.Their transition from conventional to unconventional battery designs is examined to identify operational flexibilities,overall energy storage/conversion efficiency and application compatibility.Finally,a list of facilities for large-scale deployment of major electrochemical energy storage routes is provided.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51708543, 51438011 and 51722811)Water Pollution Control and Treatment National Science and Technology Major Project (Nos. 2017ZX07402001 and 2018ZX07110-007)。
文摘Electrochemical reduction of water to hydrogen(H2) offers a promising strategy for production of clean energy,but the design and optimization of electrochemical apparatus present challenges in terms of H2 recovery and energy consumption.Using cobalt phosphide nanoarrays(Co2 P/CoP NAs) as a charge mediator,we effectively separated the H2 and O2 evolution of alkaline water electrolysis in time,thereby achieving a membrane-free pathway for H2 purification.The hierarchical array structure and synergistic optimization of the electronic configuration of metallic Co2 P and metalloid CoP make the Co2 P/CoP NAs high-efficiency bifunctional electrocatalysts for both charge storage and hydrogen evolution.Theoretical investigations revealed that the introduction of Co2 P into CoP leads to a moderate hydrogen adsorption free energy and low water dissociation barrier,which are beneficial for boosting HER activity.Meanwhile,Co2 P/CoP NAs with high capacitance could maintain a cathodic H2 evolution time of 1500 s at 10 mA cm^(-2) driven by a low average voltage of 1.38 V.Alternatively,the energy stored in the mediator could be exhausted via coupling with the anodic oxidation of ammonia,whereby only 0.21 V was required to hold the current for 1188 s.This membrane-free architecture demonstrates the potential for developing hydrogen purification technology at low cost.
文摘As the world works to move away from traditional energy sources,effective efficient energy storage devices have become a key factor for success.The emergence of unconventional electrochemical energy storage devices,including hybrid batteries,hybrid redox flow cells and bacterial batteries,is part of the solution.These alternative electrochemical cell configurations provide materials and operating condition flexibility while offering high-energy conversion efficiency and modularity of design-to-design devices.The power of these diverse devices ranges from a few milliwatts to several megawatts.Manufactur-ing durable electronic and point-of-care devices is possible due to the development of all-solid-state batteries with efficient electrodes for long cycling and high energy density.New batteries made of earth-abundant metal ions are approaching the capacity of lithium-ion batteries.Costs are being reduced with the advent of flow batteries with engineered redox molecules for high energy density and membrane-free power generating electrochemical cells,which utilize liquid dynamics and interfaces(solid,liquid,and gaseous)for electrolyte separation.These batteries support electrode regeneration strategies for chemical and bio-batteries reducing battery energy costs.Other batteries have different benefits,e.g.,carbon-neutral Li-CO_(2) batteries consume CO_(2) and generate power,offering dual-purpose energy storage and carbon sequestration.This work considers the recent technological advances of energy storage devices.Their transition from conventional to unconventional battery designs is examined to identify operational flexibilities,overall energy storage/conversion efficiency and application compatibility.Finally,a list of facilities for large-scale deployment of major electrochemical energy storage routes is provided.
