基于脱锂电压的磷酸铁钠电化学性能调控研究  

Electrochemical Performance Research of Sodium Iron Phosphate Based on Delithiation Voltage

作　　者：李鑫[1] 丁浩 蔡星鹏 牛磊[1,2] 李世友 LI Xin;DING Hao;CAI Xingpeng;NIU Lei;LI Shiyou(College of Petrochemical Technology,Lanzhou University of Technology,Lanzhou,730050,China;Gansu Key Laboratory of Low-Carbon Energy and Chemical Engineering,Lanzhou,730050,China)

机构地区：[1]兰州理工大学石油化工学院,甘肃兰州730050 [2]甘肃省低碳能源化工重点实验室,甘肃兰州730050

出　　处：《盐湖研究》2025年第2期71-78,共8页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(22269012);甘肃省教育厅产业支撑计划项目(2021CYZC-18)。

摘　　要：由于钠资源丰富且成本低廉,钠离子电池(SIBs)有望成为解决可再生能源存储与分配难题的储能器件,开发高性能正极材料是SIBs实现产业化应用的关键。磷酸铁钠(NaFePO_(4))具有成本低廉和安全性好等优点,受到人们的广泛关注。然而,Na+半径相对较大,导致其扩散动力学较慢,致使NaFePO_(4)倍率性能较差,限制了其进一步应用。本文通过调控LiFePO4脱锂电压进行电化学嵌钠,成功合成出NaFePO_(4)材料。结果表明,当脱锂电压为4.4 V,通过电化学嵌钠合成出的NaFePO_(4)材料在25℃、0.5 C(1 C=154 mAh g^(-1))下循环50次后仍然具有78.23 mAh g^(-1)的放电比容量,容量保持率高达96.97%。同时,其在2 C的倍率下仍然具有62.98 mAh g^(-1)的放电比容量。脱锂电压为4.4 V时有效提高了NaFePO_(4)材料的晶格间距,利于Na+的脱嵌,从而在一定程度上提高了NaFePO_(4)材料的倍率性能。钠离子电池正极材料的研究对于缓解锂资源稀缺问题以及提高电池性能都具有重要的意义。Due to the abundant sodium resources and low cost,sodium ion batteries(SIBs)are expected to become energy storage devices that solve the problem of renewable energy storage and distribution.The development of high-performance cathode materials is the key to achieving industrial application of SIBs.NaFePO_(4) has received extensive attention because of its low cost and safety.However,the relatively large Na+radius results in slower diffusion kinetics,leading to poor rate performance of NaFePO_(4) and limiting its further application.By regulating the lithium removal voltage of LiFePO4 for electrochemical sodium insertion,NaFePO_(4) material was successfully synthesized.The results showed that when the delithiation voltage was 4.4 V,the NaFePO_(4) material synthesized by electrochemical sodium insertion still had a discharge specific capacity of 78.23 mAh g^(-1) after 50 cycles at 0.5 C(1C=154 mAh g^(-1))in 25℃,with a capacity retention rate of up to 96.97%.Meanwhile,it still has a discharge specific capacity of 62.98 mAh g^(-1) at a rate of 2 C.When the lithium removal voltage is 4.4 V,the lattice spacing of NaFePO_(4) material is effectively increased,which is conducive to the deintercalation of Na+and thus improves the rate performance of NaFePO_(4) material to a certain extent.The research on positive electrode materials for sodium ion batteries is of great significance for alleviating the scarcity of lithium resources and improving battery performance.

关 键 词：钠离子电池 正极材料 NaFePO_(4) 电化学 

分 类 号：TM912[电气工程—电力电子与电力传动] O646.5[理学—物理化学]