In this work,we revisit and show how the structural and photoluminescent properties of the MgGa_(2)O_(4) ceramic compound have been kept unchanged for more than two decades.The obtained results confirm the high qualit...In this work,we revisit and show how the structural and photoluminescent properties of the MgGa_(2)O_(4) ceramic compound have been kept unchanged for more than two decades.The obtained results confirm the high quality,radiative efficiency,and chemical stability of this ceramic,proving that the material is a strong candidate to be used in optical device applications with relatively long useful life.展开更多
Previous studies have found that the ceramic fuel cell using Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2)(NCAL)symmetrical electrode has obtained very good power generation performance in the temperature range of 450 to 550℃.Pr...Previous studies have found that the ceramic fuel cell using Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2)(NCAL)symmetrical electrode has obtained very good power generation performance in the temperature range of 450 to 550℃.Previous studies have pointed out that after being reduced by H2,NCAL anode will produce LiOH/Li2CO3 mixture and diffuse into the electrolyte,which results in the high ionic conductivity of the cell.In this study,the chemical reactivity of different oxide electrolytes such as CeO_(2),TiO_(2),ZrO_(2)and YSZ with LiOH and/or Li2CO3 and their effects on the electrochemical performance of the cell were studied.It is found that at 550◦C,only the open circuit voltage(OCV)of the cell using CeO_(2)as electrolyte can remain stable,and the maximum power density(MPD)of the CeO_(2)electrolyte cell reaches 599.6 mW⋅cm^(−2).The OCV of the cells with TiO_(2),ZrO_(2)and YSZ as electrolyte increased to the highest value within a few minutes,and the MPD of the cells was only more than 12 mW⋅cm^(−2).XRD,FT-IR,SEM-EDS and ICP-OES results indicate that the LiOH/Li2CO3 mixture diffuses into TiO_(2),ZrO_(2)and YSZ electrolytes and reacts with three oxides to produce Li2TiO3 and Li2ZrO3,respectively,which results in the low performance of the cell.展开更多
Multilayer ceramic capacitors(MLCCs)play a crucial role in pulsed power applications because of their rapid charge/discharge capabilities.However,the combination of high energy density and high efficiency is the main ...Multilayer ceramic capacitors(MLCCs)play a crucial role in pulsed power applications because of their rapid charge/discharge capabilities.However,the combination of high energy density and high efficiency is the main challenge in practical applications.This study presents barium titanate-based(BaTiO_(3)-)lead-free relaxor ferroelectric(RFE)MLCCs formulated with 0.84BaTiO_(3)–0.16Bi(Mg_(0.2)Ni_(0.2)Zn_(0.2)Zr_(0.2)Nb_(0.2))O_(3)(0.84BT–0.16BMNZZN)and platinum inner electrodes via a tape-casting method.The introduction of the high-entropy component BMNZZN effectively enhances the relaxation behavior and local nanodomains while promoting grain refinement,resulting in a comprehensive improvement in insulation performance and energy storage performance.As a result,MLCCs exhibit excellent recoverable energy density(W_(rec)=15.7 J∙cm^(−3))and ultrahigh efficiency(η)of 96.4%(@1614 kV∙cm−1),simultaneously showing good temperature stability over a range of−120‒100℃(W_(rec)≈8.9 J∙cm^(−3)with a variation of less than±4.85%,@1078 kV∙cm−1)and excellent fatigue resistance(W_(rec)≈9.2 J∙cm^(−3)with a variation of less than±0.82%over 107 cycles,andηgreater than 95%,@1078 kV∙cm−1).These findings indicate that BT–BMNZZN RFE MLCCs offer a viable solution for high-power energy storage capacitors.展开更多
基金S.S.Pedro,M.A.F.M.da Silva,A.López,and L.P.Sosman acknowledge FAPERJ and FINEP for financial support.
文摘In this work,we revisit and show how the structural and photoluminescent properties of the MgGa_(2)O_(4) ceramic compound have been kept unchanged for more than two decades.The obtained results confirm the high quality,radiative efficiency,and chemical stability of this ceramic,proving that the material is a strong candidate to be used in optical device applications with relatively long useful life.
基金the National Natural Science Foundation of China(No.21978044,No.51834004)。
文摘Previous studies have found that the ceramic fuel cell using Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2)(NCAL)symmetrical electrode has obtained very good power generation performance in the temperature range of 450 to 550℃.Previous studies have pointed out that after being reduced by H2,NCAL anode will produce LiOH/Li2CO3 mixture and diffuse into the electrolyte,which results in the high ionic conductivity of the cell.In this study,the chemical reactivity of different oxide electrolytes such as CeO_(2),TiO_(2),ZrO_(2)and YSZ with LiOH and/or Li2CO3 and their effects on the electrochemical performance of the cell were studied.It is found that at 550◦C,only the open circuit voltage(OCV)of the cell using CeO_(2)as electrolyte can remain stable,and the maximum power density(MPD)of the CeO_(2)electrolyte cell reaches 599.6 mW⋅cm^(−2).The OCV of the cells with TiO_(2),ZrO_(2)and YSZ as electrolyte increased to the highest value within a few minutes,and the MPD of the cells was only more than 12 mW⋅cm^(−2).XRD,FT-IR,SEM-EDS and ICP-OES results indicate that the LiOH/Li2CO3 mixture diffuses into TiO_(2),ZrO_(2)and YSZ electrolytes and reacts with three oxides to produce Li2TiO3 and Li2ZrO3,respectively,which results in the low performance of the cell.
基金funding from the Natural Science Foundation of Shanghai(Grant No.21ZR1473100)the National Natural Science Foundation of China(Grant Nos.U2002217,51831010,and 5227130).
文摘Multilayer ceramic capacitors(MLCCs)play a crucial role in pulsed power applications because of their rapid charge/discharge capabilities.However,the combination of high energy density and high efficiency is the main challenge in practical applications.This study presents barium titanate-based(BaTiO_(3)-)lead-free relaxor ferroelectric(RFE)MLCCs formulated with 0.84BaTiO_(3)–0.16Bi(Mg_(0.2)Ni_(0.2)Zn_(0.2)Zr_(0.2)Nb_(0.2))O_(3)(0.84BT–0.16BMNZZN)and platinum inner electrodes via a tape-casting method.The introduction of the high-entropy component BMNZZN effectively enhances the relaxation behavior and local nanodomains while promoting grain refinement,resulting in a comprehensive improvement in insulation performance and energy storage performance.As a result,MLCCs exhibit excellent recoverable energy density(W_(rec)=15.7 J∙cm^(−3))and ultrahigh efficiency(η)of 96.4%(@1614 kV∙cm−1),simultaneously showing good temperature stability over a range of−120‒100℃(W_(rec)≈8.9 J∙cm^(−3)with a variation of less than±4.85%,@1078 kV∙cm−1)and excellent fatigue resistance(W_(rec)≈9.2 J∙cm^(−3)with a variation of less than±0.82%over 107 cycles,andηgreater than 95%,@1078 kV∙cm−1).These findings indicate that BT–BMNZZN RFE MLCCs offer a viable solution for high-power energy storage capacitors.
