High proton conductivity is reported for unhumidified ammonium borosulfate, NH₄[B(SO₄)₂], a solid acid coordination polymer that contains 1D, hydrogen‐bonded NH₄⁺···¹_∞[B(SO₄)_4/2]⁻ chains. NH₄[B(SO₄)₂] is thermally stable to 320 °C and is amenable to sintering into monolithic, polycrystalline discs at 200 °C and about 300 MPa of uniaxial pressure. Impedance spectroscopy measurements reveal ionic conductivities for sintered ammonium borosulfate of 0.1 mS cm⁻¹ at 25 °C and up to 10 mS cm⁻¹ at 180 °C in ambient air. No superprotonic transition is observed in the temperature range of 25–180 °C. Ab initio molecular dynamics simulations show these high conductivities are aided by free rotation of the NH₄⁺ units and significant gyrational mobility of the SO₄ tetrahedra, which, in turn, provide facile pathways for proton locomotion. High conductivities, a wide operational temperature window, and tolerance to both ambient and anhydrous conditions make NH₄[B(SO₄)]₂ an attractive candidate electrolyte for intermediate‐temperature hydrogen fuel cells that may enable operation at temperatures as high as 300 °C without active humidification.

中文翻译：

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硼酸铵（中温未湿固体酸聚电解质）中的质子传输容易。

高的质子传导性被报告为不增湿铵borosulfate，NH ₄ [B（SO ₄）₂ ]，包含1D，氢键合的NH的固体酸的配位聚合物₄ ⁺ ... ¹ _∞ [B（SO ₄）_4/2 ] ^-链。NH ₄ [B（SO ₄）₂ ]对热稳定至320°C，并易于在200°C和约300 MPa的单轴压力下烧结成单片多晶盘。阻抗谱测量表明，在25°C和最高10 mS cm ^-1的条件下，烧结的硼硫酸铵0.1 mS cm ^-1的离子电导率在180°C的环境空气中。在25–180°C的温度范围内未观察到超质子转变。从头算分子动力学模拟表明，这些高电导率受NH ₄ ⁺单元的自由旋转和SO ₄四面体的明显回旋运动的辅助，这反过来又为质子运动提供了便捷的途径。高电导率，宽广的工作温度范围以及对环境和无水条件的耐受性使NH ₄ [B（SO ₄）] ₂成为中温氢燃料电池的有吸引力的候选电解质，可在高达300°C的温度下运行C没有主动加湿。