In this work, we study and compare the electrochemical performance of Li-ion battery (LIB) with and without a BiFe0.95Cu0.05O3 thin film coating. The BiFe0.95Cu0.05O3 thin film is deposited on both LiNi0.5Mn0.3Co0.2O2 (NMC532) cathode and graphite anode electrodes using radio frequency magnetron sputtering. By using galvanostatic charge–discharge measurements, we observe that, in contrast to LIB without BiFe0.95Cu0.05O3 coating, the charging curve of LIB with BiFe0.95Cu0.05O3 coating exhibits a counterintuitive negative slope of the negative electron compressibility (NEC) with a rate of NEC equal to −16.36 × 10−11 meV per electron per cm2. Importantly, we find that the NEC effect has the potential to enhance the energy density in LIB with BiFe0.95Cu0.05O3 coating. The energy density of the first discharge cycle is dramatically increased from 190 Wh/kg for pristine LIB to 255 Wh/kg for LIB coated with the BiFe0.95Cu0.05O3 film. We suggest the origin of this with the change in Mott gap and a concept to apply the NEC effect for enhancing energy density LIB batteries.

中文翻译：

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负电子压缩薄膜涂层提高LiNi0.5Mn0.3Co0.2O2电池的能量密度


在这项工作中，我们研究并比较了有和没有 BiFe0.95Cu0.05O3 薄膜涂层的锂离子电池 (LIB) 的电化学性能。使用射频磁控溅射将 BiFe0.95Cu0.05O3 薄膜沉积在 LiNi0.5Mn0.3Co0.2O2 (NMC532) 阴极和石墨阳极电极上。通过恒电流充放电测量，我们观察到，与没有 BiFe0.95Cu0.05O3 涂层的 LIB 相比，有 BiFe0.95Cu0.05O3 涂层的 LIB 的充电曲线表现出与直觉相反的负电子压缩率 (NEC) 负斜率， NEC 速率等于每 cm2 每个电子 -16.36 × 10−11 meV。重要的是，我们发现NEC效应有可能提高BiFe0.95Cu0.05O3涂层LIB的能量密度。首次放电循环的能量密度从原始LIB的190 Wh/kg显着增加到涂有BiFe0.95Cu0.05O3薄膜的LIB的255 Wh/kg。我们认为其根源在于莫特间隙的变化以及应用NEC效应来提高锂离子电池能量密度的概念。