Ting DENG, Shuaiqiang JIA, Shitao HAN, et al. Electrochemical CO2 reduction to C2+ products with Cu/Zn intermetallic compounds synthesized by simple electrodeposition. P80–88
The promotion of electrochemical CO2 reduction (ECR) for use in fuels or chemicals will hopefully address global warming and energy crisis. Among many metallic catalysts applied in ECR, Cu has been considered the most promising metallic catalyst for ECR industrial applications because it favorably combines with most intermediates of ECR to produce a variety of high-value-added multi-carbon (C2+) products. However, the selectivity of Cu for specific products remains poor in ECR, which seriously increases the difficulty and cost of product purification in practical industrial applications. Intermetallic compounds (IMCs) have precise atomic structures and unique electronic properties, making them excellent catalysts. However, complex preparation methods hinder precise microstructure control, impeding the identification of active sites. This work reports a one-step electrodeposition method to introduce Zn, a metal with weak *CO binding energy, into Cu-based catalysts to form Cu/Zn IMCs. This method is not only simple but also greatly improves the electrocatalytic performance. As a result of synthetic tunability, we were able to reveal the role of Cu/Zn IMCs in promoting C2+ products, which together lead to enhancement of the Faradaic efficiency of C2+ products and enhancement of the current density in the ECR compared with counterparts of pure Cu. This work offers novel ways to control the synthesis of precise intermetallic structures and provides insights for designing advanced ECR catalysts.
2023,17 (6)
2023,17 (5)
Min HONG, Zhiyong WANG, Zhangqin SHI, et al. Three-dimensional composite Li metal anode by simple mechanical modification for high-energy batteries. P569–584
Compared with traditional graphite or newly-emerged Si-based electrode, Li metal is recognized as one of the most promising anode materials for next generation high energy density batteries on account of its ultrahigh theoretical capacity and lowest redox potential. But the “hostless” deposition problem lacks focus and remains unsolved. Fortunately, a series of composite Li metal anodes with a three-dimensional (3D) current collector has been proposed to tackle the “hostless” deposition problem by maintaining a stable electrode volume. Moreover, this design has been shown to be also effective on dendrite suppression since the increased surface area lowers local current density. Various types of 3D (and/or) composite Li anode have been developed successfully based on the softness and ductility of Li metal using simple mechanical modifications, which get rid of harsh experimental conditions, high temperatures, complex procedures, and the necessity of delicate instruments. At the very beginning, an intuitively 3D structured Li metal was fabricated by the simple mechanical surface modification technique, such as the mechanical micro-needle or the mechanical roll-press technique. In the following sections of this mini review, we summarized recently published works relating to this mechanical strategy. We hope this mini review may help to highlight the significance and effectiveness of this mechanical technique, and promise its future success in other battery chemistries based on metal anodes.
2023,17 (4)
Yu CAI, Qiang LI, Feihong DU, et al. Polymeric nanocomposites for electrocaloric refrigeration. p450–462
Electrocaloric refrigeration represents an alternative solid-state cooling technology that has the potential to reach the ultimate goal of achieving zero-global-warming potential, highly efficient refrigeration, and heat pumps. To date, both polymeric and inorganic oxides have demonstrated giant electrocaloric effect as well as respective cooling devices. To date, substantial electrocaloric effects have been demonstrated in both polymeric and inorganic oxide materials, leading to the development of respective cooling devices. Despite their promise, these two approaches — polymeric and inorganic oxide-based — encounter notable challenges that impede their practical implementation. From the perspective of electrocaloric materials, a viable solution emerges in the form of electrocaloric nanocomposites, which hold the promise of amalgamating the advantageous attributes of organic and inorganic electrocaloric materials. This review provides a comprehensive and in-depth understanding of recent developments of polymeric nanocomposites for electrocaloric refrigeration, mainly focusing on the electrocaloric effect, thermal and mechanical performances. Besides, the extant impediments and potential prospects associated with the integration of electrocaloric nanocomposites into practical cooling applications has also been revealed.
2023,17 (3)
Yawen ZHENG, Lin GAO, Song HE, et al. Reduction potential of the energy penalty for CO2 capture in CCS. p390–399
The first-generation CO2 capture technology, known as post-combustion capture, involves capturing low-concentration CO2 from flue gas produced by fossil fuel combustion. However, this technology is associated with high energy consumption and costs, which hinders the deployment of CCUS (Carbon Capture, Utilization, and Storage) in power plants. Innovations in CO2 capture technology can be achieved by exploring new fuel conversion methods, which can facilitate CO2 separation or directly realize fully enrichment of CO2 to avoid separation. On the one hand, a higher CO2 concentration can promise lower or even near zero energy consumption in separation, and on the other hand, better chemical energy utilization can compensate for the efficiency reduction due to CO2 separation. Exploration of fuel conversion paths with coupling effects, so-called “source control technology”, provides a new dimension for reducing the penalty of CO2 capture technology in addition to improving the efficiency of CO2 separation technology.
2023,17 (2)
Challenged by carbon emission and energy utilization efficiency, traditional energy systems are undergoing a profound transformation from the system structure to the consumption mode. Represented by microgrids and integrated energy systems (IES), the concept and development have advanced the coordinated usage of renewable energy generation and energy storage, which can effectively meet energy demands across all sectors. Microgrids and IES have attracted more attention nowadays to facilitate the reliable and efficient operation of energy systems.
The adoption of microgrid and IES significantly increases the coupling and interactions between sources and between supply and end-use at various scales. Flexibility and resilience of distribution networks can be achieved based on the multiple energy integration in microgrids and IES, e.g., electricity, heat, cooling, and other energy service requirements. Thus, there is a growing call for the development of advanced modeling, simulation, optimization and planning tools of microgrids and IES, which will lead to a more efficient and sustainable energy system.
This special column is a state-of-art collection on the theories and practices involving microgrids and IES. The aim is to disseminate the latest advances on architecture design, novel methodologies, and pilot applications of microgrids and IES. It also provides a valuable opportunity for researchers and engineers to share their discoveries and practices in these areas.
2023,17 (1)
(Ya-Ling HE, Wenqi WANG, Rui JIANG, et al. p16-42)
Concentrating solar power (CSP) is a technology that converts solar energy to heat, then to electricity. CSP can provide dispatchable electricity due to its intrinsic thermal storage capacity, which is able to deal with the intermittency and fluctuation of solar energy resources. Therefore, CSP is one of the most promising power technologies for China’s “dual carbon” goal. However, the levelized cost of energy (LCOE) of current CSP is still high. To reduce the LCOE, the outlet temperature of the solar receiver will be elevated to >700 °C in the next-generation CSP. Because of extensive engineering application experience, the liquid-based receiver is an attractive receiver technology for the next-generation CSP. This review is focused on four of the most promising liquid-based receivers, including chloride salts, sodium, lead-bismuth, and tin receivers. The challenges of these receivers and corresponding solutions are comprehensively reviewed and classified. In the end, suggestions for future studies are proposed to bridge the research gaps for > 700 °C liquid-based receivers.
(Ya-Ling HE, Wenqi WANG, Rui JIANG, et al. p16-42)
Concentrating solar power (CSP) is a technology that converts solar energy to heat, then to electricity. CSP can provide dispatchable electricity due to its intrinsic thermal storage capacity, which is able to deal with the intermittency and fluctuation of solar energy resources. Therefore, CSP is one of the most promising power technologies for China’s “dual carbon” goal. However, the levelized cost of energy (LCOE) of current CSP is still high. To reduce the LCOE, the outlet temperature of the solar receiver will be elevated to >700 °C in the next-generation CSP. Because of extensive engineering application experience, the liquid-based receiver is an attractive receiver technology for the next-generation CSP. This review is focused on four of the most promising liquid-based receivers, including chloride salts, sodium, lead-bismuth, and tin receivers. The challenges of these receivers and corresponding solutions are comprehensively reviewed and classified. In the end, suggestions for future studies are proposed to bridge the research gaps for > 700 °C liquid-based receivers.
2022,16 (6)
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Jin XIAO, Yingdong CHENG, Jinlong WANG, et al. An experimental study of a single-piston free piston linear generator. p916-930
To mitigate the environmental and health problems caused by vehicle emissions, free piston linear generator (FPLG) is considered as an alternative solution which can be realized in the near future. It can be regarded as a device consisting of a crankshaft-less internal combustion engine, a linear electric machine and a rebounding device like gas spring. Because of the absence of the crankshaft restriction, its compression ratio is variable and controllable without modifying the mechanical configuration, so that it is available for various fuel, especially the clean fuel such as the ethanol, hydrogen, methane and natural gas and so forth. Consequently, FPLG receives increasing attention from the public.
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Jin XIAO, Yingdong CHENG, Jinlong WANG, et al. An experimental study of a single-piston free piston linear generator. p916-930
To mitigate the environmental and health problems caused by vehicle emissions, free piston linear generator (FPLG) is considered as an alternative solution which can be realized in the near future. It can be regarded as a device consisting of a crankshaft-less internal combustion engine, a linear electric machine and a rebounding device like gas spring. Because of the absence of the crankshaft restriction, its compression ratio is variable and controllable without modifying the mechanical configuration, so that it is available for various fuel, especially the clean fuel such as the ethanol, hydrogen, methane and natural gas and so forth. Consequently, FPLG receives increasing attention from the public.
2022,16 (5)
Solid-state electrolytes (SSEs) deliver inherent advantage of safety over the organic liquid system in rechargeable lithium batteries. However, the single use of polymer or ceramic SSEs can never meet the demand although great progress has been made in the past few years. Composite solid electrolytes (CSEs) composed of flexible polymers and brittle but active ceramics can take advantage of the individual system for solid-state lithium metal batteries (SSLMBs). According to the mass fraction of components, CSEs can be largely divided into two categories, namely “polymer rich” (PR) and “ceramic rich” (CR) systems with different internal structures and properties. This review provides a comprehensive and in-depth understanding of recent advances and limitations of both PR and CR electrolytes, mainly focusing on the ion conduction path based on interphase interactions and the structural designs of ceramic fillers/frameworks. Besides, the fact that PR and CR can bring the leverage between the electrochemical and the mechanical property has also been revealed. Moreover, it further prospects the possible route for future development of CSEs according to their rational design, conducive to the expectant industrialized application in SSLMBs.
Solid-state electrolytes (SSEs) deliver inherent advantage of safety over the organic liquid system in rechargeable lithium batteries. However, the single use of polymer or ceramic SSEs can never meet the demand although great progress has been made in the past few years. Composite solid electrolytes (CSEs) composed of flexible polymers and brittle but active ceramics can take advantage of the individual system for solid-state lithium metal batteries (SSLMBs). According to the mass fraction of components, CSEs can be largely divided into two categories, namely “polymer rich” (PR) and “ceramic rich” (CR) systems with different internal structures and properties. This review provides a comprehensive and in-depth understanding of recent advances and limitations of both PR and CR electrolytes, mainly focusing on the ion conduction path based on interphase interactions and the structural designs of ceramic fillers/frameworks. Besides, the fact that PR and CR can bring the leverage between the electrochemical and the mechanical property has also been revealed. Moreover, it further prospects the possible route for future development of CSEs according to their rational design, conducive to the expectant industrialized application in SSLMBs.
2022,16 (4)
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Lifu YAN, Lingling ZHAO, Guiting YANG, et al. High performance solid-state thermoelectric energy conversion via inorganic metal halide perovskites under tailored mechanical deformation. p581-594
Solid-state thermoelectric energy conversion via the Seebeck effect is widely considered to be a leading option for recovering the waste heat and improving the primary energy efficiency. However, the energy conversion efficiency of such device is significantly limited by the thermoelectric materials. Recently, metal halide perovskites ABX3 emerged as a low-cost, solution-processable thermoelectric material, mainly due to superior electronic transport properties and ultralow thermal conductivity. This work demonstrates that halogen mixing, combined with mechanical deformation, can tailor the electronic band structures and charge carrier transport properties of CsPb(I1-xBrx)3 synergistically. The theoretical power generation efficiency of the corresponding thermoelectric device can reach ~12%, when the heat source is at 500 K and the cold side is maintained at 300 K, surpassing the performance of many existing bulk thermoelectric materials.
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Lifu YAN, Lingling ZHAO, Guiting YANG, et al. High performance solid-state thermoelectric energy conversion via inorganic metal halide perovskites under tailored mechanical deformation. p581-594
Solid-state thermoelectric energy conversion via the Seebeck effect is widely considered to be a leading option for recovering the waste heat and improving the primary energy efficiency. However, the energy conversion efficiency of such device is significantly limited by the thermoelectric materials. Recently, metal halide perovskites ABX3 emerged as a low-cost, solution-processable thermoelectric material, mainly due to superior electronic transport properties and ultralow thermal conductivity. This work demonstrates that halogen mixing, combined with mechanical deformation, can tailor the electronic band structures and charge carrier transport properties of CsPb(I1-xBrx)3 synergistically. The theoretical power generation efficiency of the corresponding thermoelectric device can reach ~12%, when the heat source is at 500 K and the cold side is maintained at 300 K, surpassing the performance of many existing bulk thermoelectric materials.
2022,16 (3)
Chuanke LIU, Zhizhu HE. P460–470
As electronic devices develop rapidly toward high-power densities and miniaturization, waste heat, as inevitable byproducts, significantly influences the electronic apparatus and even induces malfunction and degradation of electronics. Recently, the room-temperature gallium-based liquid metal has been expected to be an ultra-high potential extreme thermal management coolant, mainly due to its superior thermal conductivity, high boiling point, low viscosity, and non-toxicity. However, its cooling capacity is significantly limited by the pumping method. The high electrical conductivity enables the liquid metal to be driven by electromagnetic force. This work developed a high-performance electromagnetic induction pump driven by rotating permanent magnets, which is then combined with the mini-channel heat sink and could dissipate a heat flux of up to 242 W/cm2. It also introduced the liquid metal thermal grease to reduce the thermal contact resistance efficiently. This work provides a powerful cooling strategy for thermal management of electric devices with a considerable heat power and high heat flux.
Chuanke LIU, Zhizhu HE. P460–470
As electronic devices develop rapidly toward high-power densities and miniaturization, waste heat, as inevitable byproducts, significantly influences the electronic apparatus and even induces malfunction and degradation of electronics. Recently, the room-temperature gallium-based liquid metal has been expected to be an ultra-high potential extreme thermal management coolant, mainly due to its superior thermal conductivity, high boiling point, low viscosity, and non-toxicity. However, its cooling capacity is significantly limited by the pumping method. The high electrical conductivity enables the liquid metal to be driven by electromagnetic force. This work developed a high-performance electromagnetic induction pump driven by rotating permanent magnets, which is then combined with the mini-channel heat sink and could dissipate a heat flux of up to 242 W/cm2. It also introduced the liquid metal thermal grease to reduce the thermal contact resistance efficiently. This work provides a powerful cooling strategy for thermal management of electric devices with a considerable heat power and high heat flux.
2022,16 (2)
(Xingchao WANG, Chunjian PAN, Carlos E. ROMERO, et al. p246–262)
CO2 capture and sequestration in deep saline aquifers is widely considered to be a leading option for controlling greenhouse gas emissions. One such possibility involves injection of supercritical carbon dioxide (sCO2) into a high-permeability geothermal reservoir. In addition to the benefit of sequestering the CO2 captured from fossil-fired power plants in reservoirs, the CO2 can be used to mine geothermal heat for utilization above ground. This study presents the capability to obtain desirable sCO2 production flow rates, temperatures and pressures for power generations in a fully coupled geothermal wellbores and reservoir system. Furthermore, a power cost analysis and optimization methodology has been developed combining of thermodynamic performance and system cost both for the geothermal heat mining system and power generation system. The power cost considered in this study is levelized cost of electricity (LCOE) in USD per kilowatt-hour ($/kWh) over the plant life. This cost estimation and optimization methodology has been applied to obtain the most cost-effective power generation system design with considering the geothermal energy extraction system, including optimal well size, well distances as well as CO2 injection flow rate, all of which s also significantly affect the system thermodynamic performance. Accordingly, the most cost-effective design with the minimal LCOE of 0.177 $/kWh was achieved for a 20-year steady operation without considering CO2 sequestration credit through the global optimization. Furthermore, the benefit from CO2 sequestration is emphasized in this study. (Xingchao WANG, Chunjian PAN, Carlos E. ROMERO, et al. p246–262)
CO2 capture and sequestration in deep saline aquifers is widely considered to be a leading option for controlling greenhouse gas emissions. One such possibility involves injection of supercritical carbon dioxide (sCO2) into a high-permeability geothermal reservoir. In addition to the benefit of sequestering the CO2 captured from fossil-fired power plants in reservoirs, the CO2 can be used to mine geothermal heat for utilization above ground. This study presents the capability to obtain desirable sCO2 production flow rates, temperatures and pressures for power generations in a fully coupled geothermal wellbores and reservoir system. Furthermore, a power cost analysis and optimization methodology has been developed combining of thermodynamic performance and system cost both for the geothermal heat mining system and power generation system. The power cost considered in this study is levelized cost of electricity (LCOE) in USD per kilowatt-hour ($/kWh) over the plant life. This cost estimation and optimization methodology has been applied to obtain the most cost-effective power generation system design with considering the geothermal energy extraction system, including optimal well size, well distances as well as CO2 injection flow rate, all of which s also significantly affect the system thermodynamic performance. Accordingly, the most cost-effective design with the minimal LCOE of 0.177 $/kWh was achieved for a 20-year steady operation without considering CO2 sequestration credit through the global optimization. Furthermore, the benefit from CO2 sequestration is emphasized in this study.
2022,16 (1)
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(Wenzhong SHEN, Yixin ZHAO, and Feng LIU, p1-8)
Scheme illustrating the key role of solar photovoltaic (PV) technology carbon neutrality and the progress of power conversion efficiency (PCE) of solar cells in 2021. Here, the certified PCE of three mainstream (silicon, perovskite and organic) solar cells in 2021 is highlighted. The global new installed solar PV capacity over the past 20 years has grown at a compound annual growth rate of ~40%, far outpacing other energy sources such as coal, oil, natural gas and wind. The strong momentum of the PV industry comes from its rapidly levelized cost of electricity due to the technological improvement and large-scale application. The Lower bid price for large-scale PV plants around the world has been reduced to 1.04 cents/kWh in 2021, and both the US and Chinese governments have announced in 2021 that the PV power generation will become the biggest power source in 20–30 years with a proportion of ~40% of the total power generation.
About the Cover Image
(Wenzhong SHEN, Yixin ZHAO, and Feng LIU, p1-8)
Scheme illustrating the key role of solar photovoltaic (PV) technology carbon neutrality and the progress of power conversion efficiency (PCE) of solar cells in 2021. Here, the certified PCE of three mainstream (silicon, perovskite and organic) solar cells in 2021 is highlighted. The global new installed solar PV capacity over the past 20 years has grown at a compound annual growth rate of ~40%, far outpacing other energy sources such as coal, oil, natural gas and wind. The strong momentum of the PV industry comes from its rapidly levelized cost of electricity due to the technological improvement and large-scale application. The Lower bid price for large-scale PV plants around the world has been reduced to 1.04 cents/kWh in 2021, and both the US and Chinese governments have announced in 2021 that the PV power generation will become the biggest power source in 20–30 years with a proportion of ~40% of the total power generation.
