【作者】 徐磊；

【导师】 孟长功； 张依福；

【作者基本信息】 大连理工大学 ， 无机化学， 2021， 硕士

【摘要】 水系锌离子电池（ZIBs）是一种新兴的能源电池,因为使用的是锌作为负极,价格低廉,并且使用的是水性电解液具有更高的安全性,对能源材料的装配要求也更低,具有极大的发展潜力。而钒作为正极材料时,其多价态的转化实现了多电子的转移,使得钒材料具有更高的理论比电容量。本文以V₂O₅和NH₄VO₃为原料,通过结构调控、离子或有机化合物插层合成ZIBs的V基正极材料。产物的形貌与结构可通过XRD、FTIR、Raman、SEM和TEM等手段进行了表征,其储锌性能则可采用循环伏安法、恒电流充放电等测试手段来分析。结果表明通过结构调控与插层改善了V基材料作为电极材料的储能效果和电荷传递效率。本论文主要内容如下:（1）通过探究并调控不同的合成条件,将原材料NH₄VO₃以一步水热合成法合成了（NH₄）₂V₆O₁₆纳米带,并将其作为电极材料用作ZIBs的正极。根据CV测试结果,（NH₄）₂V₆O₁₆在0.3-1.7 V区间内表现出稳定的循环性能。在0.1 A·g^-1下,（NH₄）₂V₆O₁₆比电容量最大可以达到323.5 m Ah·g^-1。在5 A·g^-1下,Zn//（NH₄）₂V₆O₁₆电池的比电容量释放最大可达238.7 m Ah·g^-1,且在2000次的循环过后,比电容量仍有78%。同时,（NH₄）₂V₆O₁₆具有良好的倍率性能。其在99 W·kg^-1下也可达到249 Wh·kg^-1的能量密度。（2）利用钒氧板层的层状特性,设计以非金属阳离子插层的方法来调控水合五氧化二钒（V₂O₅·n H₂O）的层状结构,从而提升电极材料的电化学性能。通过水热合成法成功合成了NH₄⁺插层的水合五氧化二钒柔性纳米带,简写成NVOH,其层间距为11.2?。作为ZIBs正极材料,CV测试表明其在0.3-1.6 V范围内具有良好的循环稳定性。在0.1 A·g^-1下,NVOH最大比电容量释放达到372 m Ah·g^-1,而在5 A·g^-1下循环2000次后,放电比电容量仍有175 m Ah·g^-1。同时,NVOH不仅在能量密度和功率密度上表现良好,还在倍率性能测试中表现出优秀的可逆性。（3）设计以界面插层法将聚苯胺（PANI）引入到V₂O₅·n H₂O层间,以实现导电高分子与钒氧层间的协同作用提高电化学性能。通过XRD、FTIR、Raman等表征手段证实了PANI被成功插层到V₂O₅·n H₂O中,简写成PANI-VOH,钒氧层间距为14.1?。在电化学测试中,PANI-VOH在倍率性能测试中表现优秀,同时在0.1 A·g^-1下,PANI-VOH最大可以释放的比电容量为363 m Ah·g^-1,在5 A·g^-1下,放电比电容量最大仍可达到270m Ah·g^-1,且2000次循环后仍有初始比电容量86%。对能量密度进行计算分析,在78W·kg^-1下能达到275 Wh·kg^-1。更多还原

【Abstract】 Aqueous zinc ion batteries（ZIBs）are an emerging type of battery.It uses zinc metal as the negative electrode,so the price is inexpensive.And the use of aqueous electrolyte also ensures higher safety characteristics of aqueous ZIBs,which means the lower assembly requirements for energy storage devices.When vanadium is used as a cathode material,the conversion of its multivalent state realizes the transfer of multiple electrons,which makes the V-based material have a higher theoretical specific capacity.In this paper,V₂O₅ and NH₄VO₃were used as raw materials to synthesize cathode materials applied for aqueous zinc ion batteries through structural optimization and adjustment,ions or organic compound intercalating.XRD,FTIR,Raman,SEM and other characterization methods were adopted to test the morphology and structure of the prepared sample.CV,GCD and other testing methods were mainly adopted to analyze the zinc storage performance,which proved the structural adjustment and intercalation way improving the energy storage effect and charge transfer efficiency of V-based materials as electrode materials.The main contents are as follow:（1）Using NH₄VO₃ as the raw material,（NH₄）₂V₆O₁₆ was synthesized by a one-step hydrothermal synthesis method after exploring and adjusting the synthesis conditions,which was used as the electrode material for the aqueous ZIBs.According to the CV test results,（NH₄）₂V₆O₁₆ has good electrochemical cycling stability in the voltage range of 0.3-1.7 V.GCD results show that the specific capacity of（NH₄）₂V₆O₁₆ electrode can reach up to a maximum value of 323.5 m Ah·g^-1 at a current density of 0.1 A·g^-1.At a current density of 5 A·g^-1,the maximum specific capacity of（NH₄）₂V₆O₁₆ can reach up to 238.7 m Ah·g^-1,and the specific capacity still keeps 78%remained after 2000 cycles.At the same time,（NH₄）₂V₆O₁₆ has good rate performance.It also can get an energy density of 249 Wh·kg^-1 at 99 W·kg^-1.（2）In order to achieve the purpose of improving the electrochemical performance,we took advantage of the layered characteristics of the vanadium oxide layers to design a non-metallic cation intercalation method controlling the layered structure of the hydrated vanadium pentoxide（V₂O₅·n H₂O）.NH₄⁺intercalated hydrated vanadium pentoxide flexible nanoribbons were successfully synthesized by the hydrothermal synthesis method,abbreviated as NVOH.The interlayer spacing of NVOH was measured to be 11.2?through various characterization methods.As a positive electrode material of ZIBs,CV test proved that it had good cycling stability in the voltage range of 0.3-1.6 V.At a current density of 0.1 A·g^-1,the discharge specific capacity of NVOH can reach up to a maximum value of 372 m Ah·g^-1.At a current density of 5 A·g^-1,GCD result shows that the discharge specific capacity is still 175 m Ah·g^-1after 2000 cycles.At the same time,NVOH also has good rate performance and excellent power density and energy density.At a power density of 155 W·kg^-1,it has an energy density of 273Wh·kg^-1.（3）In order to improve electrochemical performance through the synergistic effect of the conductive polymer and the vanadium oxide layers,we designed an interface intercalation method to introduce polyaniline（PANI）between the V₂O₅·n H₂O layers.It has been confirmed that PANI was successfully intercalated into the V₂O₅·n H₂O by XRD,FTIR,Raman and other characterization methods,abbreviated as PANI-VOH.The vanadium oxide layer spacing of PANI-VOH was measured to be 14.1?.In the electrochemical tests,PANI-VOH shows excellent rate performance.At a current density of 0.1 A·g^-1,PANI-VOH can reach up to a maximum specific capacity of 363 m Ah·g^-1.The discharge capacity of PANI-VOH can reach up to be 270 m Ah·g^-1 at a current density of 5 A·g^-1,and the capacity still keep 86%remained of initial capacity after 2000 cycles.Through calculation and analysis,the energy density of PANI-VOH can reach up to be 275 Wh·kg^-1 at 78 W·kg^-1.更多还原