Jin Ting, Li Huangxu, Zhu Kunjie, Wang Peng-Fei, Liu Pei, Jiao Lifang
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (ReCast), College of Chemistry, Nankai University, Tianjin 300071, China.
Chem Soc Rev. 2020 Apr 21;49(8):2342-2377. doi: 10.1039/c9cs00846b. Epub 2020 Mar 29.
Room-temperature sodium-ion batteries (SIBs) are regarded as promising candidates for smart grids and large-scale energy storage systems (EESs) due to their significant benefits of abundant and low-cost sodium resource. Among the previously reported cathode materials for SIBs, layered transition-metal oxides and polyanion-type materials are considered to be the most attractive options. Although many layered transition-metal oxides can provide high capacity due to their small molecular weight, their further application is hindered by low output voltage (mostly lower than 3.5 V), irreversible phase transition as well as storage instability. Comparatively, polyanion-type materials exhibit higher operating potentials due to the inductive effect of polyanion groups. Their robust 3D framework significantly decreases the structural variations during sodium ion de/intercalation. Moreover, the effect of strong X-O (X = S, P, Si, etc.) covalent bonds can effectively inhibit oxygen evolution. These advantages contribute to the superior cycle stability and high safety of polyanion-type materials. However, low electronic conductivity and limited capacity still restrict their further application. This review summarizes the recent progress of polyanion-type materials for SIBs, which include phosphates, fluorophosphates, pyrophosphates, mixed phosphates, sulfates, and silicates. We also discuss the remaining challenges and corresponding strategies for polyanion-type materials. We hope this review can provide some insights into the development of polyanionic materials.
室温钠离子电池（SIBs）因其钠资源丰富且成本低廉的显著优势，被视为智能电网和大规模储能系统（EESs）的理想候选者。在先前报道的用于SIBs的阴极材料中，层状过渡金属氧化物和聚阴离子型材料被认为是最具吸引力的选择。尽管许多层状过渡金属氧化物因其分子量小而能提供高容量，但其进一步应用受到低输出电压（大多低于3.5V）、不可逆相变以及储存不稳定性的阻碍。相比之下，聚阴离子型材料由于聚阴离子基团的诱导效应而表现出更高的工作电位。其坚固的三维框架显著减少了钠离子脱嵌/嵌入过程中的结构变化。此外，强X-O（X = S、P、Si等）共价键的作用可有效抑制析氧。这些优势促成了聚阴离子型材料卓越的循环稳定性和高安全性。然而，低电子电导率和有限的容量仍然限制了它们的进一步应用。本文综述了用于SIBs的聚阴离子型材料的最新进展，包括磷酸盐、氟磷酸盐、焦磷酸盐、混合磷酸盐、硫酸盐和硅酸盐。我们还讨论了聚阴离子型材料仍然存在的挑战及相应策略。我们希望这篇综述能为聚阴离子材料的发展提供一些见解。
