Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making th...Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn^(2+)hinder their development.Herein,we present a highperformance thermal charging cell design using Zn^(2+)/NH_(4)^(+)hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH_(4)^(+).Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K^(-1)and an excellent normalized power density of 19.6 mW m^(-2)K^(-2)at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.展开更多
通过水热改性氢氧化锆制备了SO42-/ZrO2固体酸催化剂。以冰乙酸和正丁醇的酯化反应为探针反应,确定了固体超强酸的最佳制备条件。分别考察了浸渍硫酸浓度、硫酸浸渍时间和焙烧温度等对催化活性的影响。并以水热改性和未经水热改性氢氧...通过水热改性氢氧化锆制备了SO42-/ZrO2固体酸催化剂。以冰乙酸和正丁醇的酯化反应为探针反应,确定了固体超强酸的最佳制备条件。分别考察了浸渍硫酸浓度、硫酸浸渍时间和焙烧温度等对催化活性的影响。并以水热改性和未经水热改性氢氧化锆制备SO42-/ZrO2固体超强酸做了对比实验,采用XRD、BET对催化剂进行了表征。实验结果表明:水热改性氢氧化锆制备SO42-/ZrO2固体酸催化剂的最佳条件是:浸渍硫酸浓度为0.5mol/L,浸渍时间是120 m in,焙烧温度500℃。乙酸正丁酯较佳的合成工艺条件是:反应温度105~110℃,反应时间2 h,n(正丁醇)∶n(冰乙酸)=2∶1,催化剂用量占反应投料总质量的0.27%,冰乙酸的酯化率达99.1%。催化剂重复使用4次后催化活性降低5%。展开更多
基金supported by the Leading Edge Technology of Jiangsu Province(BK20222009-X.Z.,BK20202008-X.Z.)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)National Undergraduate Innovation Training Program of NUAA(202410287179Y).
文摘Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn^(2+)hinder their development.Herein,we present a highperformance thermal charging cell design using Zn^(2+)/NH_(4)^(+)hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH_(4)^(+).Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K^(-1)and an excellent normalized power density of 19.6 mW m^(-2)K^(-2)at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.
文摘通过水热改性氢氧化锆制备了SO42-/ZrO2固体酸催化剂。以冰乙酸和正丁醇的酯化反应为探针反应,确定了固体超强酸的最佳制备条件。分别考察了浸渍硫酸浓度、硫酸浸渍时间和焙烧温度等对催化活性的影响。并以水热改性和未经水热改性氢氧化锆制备SO42-/ZrO2固体超强酸做了对比实验,采用XRD、BET对催化剂进行了表征。实验结果表明:水热改性氢氧化锆制备SO42-/ZrO2固体酸催化剂的最佳条件是:浸渍硫酸浓度为0.5mol/L,浸渍时间是120 m in,焙烧温度500℃。乙酸正丁酯较佳的合成工艺条件是:反应温度105~110℃,反应时间2 h,n(正丁醇)∶n(冰乙酸)=2∶1,催化剂用量占反应投料总质量的0.27%,冰乙酸的酯化率达99.1%。催化剂重复使用4次后催化活性降低5%。
