Thermal behaviour of tin(II/IV) phosphates prepared by various methods

A high-energy hybrid lithium-ion capacitor enabled by a mixed capacitive-battery storage LiFePO4 – AC cathode and a SnP2O7 – rGO anode

“…Further increase in the temperature promotes the carbothermal reduction of phosphorous-tin composites leading to the formation of metallic Sn while releasing phosphorouscontaining gases. 20,39 SEM images registered for the different thermal treated samples show the morphological differences between the three materials expected from the XRD results. Fig.…”

“…Further increase in the temperature promotes the carbothermal reduction of phosphorous-tin composites leading to the formation of metallic Sn while releasing phosphorous-containing gases. 20,39…”

Development of In Situ Formed Metal Pyrophosphates (MP2O7, Where M = Sn, Ti, and Zr)/PA/PBI Based Composite Membranes for Fuel Cells

“…For example, Sn(HPO 4 ) 2 was formed after calcined at 250 °C for 8 h and further increase of heat treatment time will dehydrate Sn(HPO 4 ) 2 , forming SnP 2 O 7 (Figure 1d). [ 28 ] Therefore, the reaction of SnO 2 , TiO 2 , and ZrO 2 with PA start from the formation of M(HPO 4 ) 2 (M = Sn, Ti, and Zr) intermediates at lower temperature, which will gradually dehydrate to form MP 2 O 7 with the increased temperature and duration. This can be shown in the following reaction steps: $$\[ \begin{array}{*{20}{c}}{{\rm{M}}{{\rm{O}}_2} + {\rm{PA}} \to {\rm{M}}{{\left( {{\rm{HP}}{{\rm{O}}_4}} \right)}_2} \to {\rm{M}}{{\rm{P}}_2}{{\rm{O}}_7}}\end{array} \]$$…”

Site-Specific Proton Dynamics in Indium-Doped Tin Pyrophosphate

“…1,9,10 Additionally, tin pyrophosphates are thermally stable up to about 850 °C and are not water-soluble. 2,11 These characteristics may result in increased stability relative to phosphate solid acids, another class of solid-state proton conductors, which have also been proposed as electrolytes for use in intermediate-temperature fuel cells. 7,12 However, creating a usable solid-state fuel cell electrolyte from tin pyrophosphate requires careful consideration as sample preparation and handling have been shown to have a significant impact on the proton conductivity of these materials.…”

“…Tin pyrophosphates, solid-state materials that are composed of a cubic network of tin octahedra and corner-sharing phosphate tetrahedra, have been proposed as potential intermediate-temperature proton conductors. ,, These materials have been shown to yield moderate proton conductivities in the 100–350 °C range, which would extend the operational temperature range when compared to phosphoric acid fuel cells which typically operate around 200 °C. ,, Higher operating temperatures would potentially increase both the proton conductivity and resistance to CO poisoning of these devices. ,, Additionally, tin pyrophosphates are thermally stable up to about 850 °C and are not water-soluble. , These characteristics may result in increased stability relative to phosphate solid acids, another class of solid-state proton conductors, which have also been proposed as electrolytes for use in intermediate-temperature fuel cells. , However, creating a usable solid-state fuel cell electrolyte from tin pyrophosphate requires careful consideration as sample preparation and handling have been shown to have a significant impact on the proton conductivity of these materials.…”