【作者】 赵越；

【导师】 孙逊； 玄晓旭；

【作者基本信息】 山东大学 ， 工业工程（专业学位）， 2022， 硕士

【摘要】 新型储能器件的超级电容器(Supercapacitor,SC),因其优异的功率密度、良好的倍率性能、长期循环稳定性和安全性而在过去几十年中被广泛关注、研究与应用,针对超级电容器普遍存在的电极材料生产成本高、孔隙结构不合理、比表面积低以及循环稳定性等关键问题,本文展开了相关研究。以蒜皮为前驱体,采用不同方法对其处理,探究了不同制备条件下生物炭孔结构及电化学性能的影响。另外,采用三聚氰胺为氮源,结合不同的预处理方法对多孔炭进行了杂原子掺杂,得到高性能的氮掺杂多孔生物炭(Porous biochar carbon,PBC),为生物质基多孔炭研究提供了有价值的参考依据。通过以蒜皮为前驱体,KOH为活化剂,验证了水力空化(Hydrodynamic cavitation,HC)辅助合成PBC的方法。对比不同制备方法对PBC孔结构、表面特性、石墨化程度,以及制备的SC电化学性能的区别,发现HC结合加碱活化对蒜皮PBC 比表面积及孔容产生了较大改变,最优制备条件下的PBC 比表面积达到了 3071 m2 g-1。总孔隙体积达到2.7 cm3 g-1;证明了 HC过程对PBC的改性具有较为明显的结果,经过HC处理的样品表面杂质被清除,证明HC是一种优秀的预处理方法。而且经过HC处理后的样品电化学性能改善明显,在双电极体系(6 MKOH)下,“KOH(1:8)+HC”样品的效果最好,在1 A g-1的电流密度下,比电容最高达到了 240 F g-1。经过在电流密度为5 A g-1下的5000次充放电循环后,“KOH(1:8)+HC”电容保留率高达96%,展现了优异的循环特性。选蒜皮为前驱体,KOH作活化剂,三聚氰胺作氮源,HC辅助处理,旨在寻求不同工艺下的PBC的性能区别,然后对所制备SC展开电化学测试。HC处理结合氮掺杂的样品微孔孔容比未经过HC但是同样氮掺杂的样品的孔容提高了 12%(由0.48 cm3 g-1增至0.6 cm3 g-1),微孔的比表面积提高了20.1%(由1207 m2 g-1增至1450 m2 g-1),微孔率由30%增加到42%,HC处理使三聚氰胺的引入增加了微孔率、微孔体积及微孔比表面积,证明了 HC结合三聚氰胺对PBC的微孔量有较大影响。在双电极体系(6 M KOH)下,“KOH(1:6)+HC+C3H6N6”样品的SC在电流密度为1 Ag-1时的比电容为305 F g-1,拥有最高的比电容,最高的能量密度及优秀的孔结构。经过5000次充放电循环(电流密度为5 A g-1)后,“KOH(1:6)+HC+C3H6N6”样品SC的电容保留率高达100%,具有极其优秀的循环特性。更多还原

【Abstract】 Supercapacitor(SC),a new type of energy storage device,have been widely concerned,researched and applied in the past few decades due to their excellent power density,good rate performance,long-term cycling stability and safety.Key issues such as high production cost,underdeveloped pore structure,low specific surface area,and cycling stability are studied in this paper.In this paper,garlic peel was used as the precursor material and treated by different methods to explore the influence of the pore structure and electrochemical performance of porous biochar under different preparation conditions.In addition,the porous carbon was doped with heteroatom by using melamine as nitrogen source and different pretreatment methods to obtain high-performance nitrogen-doped porous biochar carbon(PBC),which provides a valuable reference for the research of porous biochar carbon in accordance with.By using garlic peel as the precursor and KOH as the activator,the method of hydrodynamic cavitation(HC)-assisted synthesis of PBC was verified.By comparing the effects of different preparation methods on the pore structure,surface properties,graphitization degree of PBC,and the electrochemical properties of the prepared SC,it was found that HC combined with alkali activation had a great influence on the specific surface area and pore volume of garlic skin-based PBC,the specific surface area of PBC under the optimal preparation conditions reached 3071 cm3 g-1.The total pore volume reaches 2.7 cm3g-1,it proves that the HC process has obvious results on the modification of PBC,and the surface impurities of the samples treated with HC are removed,which proves that HC is an excellent pretreatment method.Moreover,the electrochemical properties of the samples treated with HC are significantly improved.Among them,the "KOH(1:8)+HC" sample has the best effect.At a current density of 1 A g-1,the specific capacitance reaches a maximum of 240 F g-1.After 5000 charge-discharge cycles at a current density of 5 A g-1,the capacitance retention rate of "KOH(1:8)+HC" is as high as 96%,indicating its good cycling characteristics.Taking garlic peel as precursor,KOH as activator,melamine as nitrogen source,and HC as auxiliary treatment.The properties of the PBCs were distinguished,and electrochemical tests were performed on the as-prepared SC.The pore volume of the sample treated with HC combined with nitrogen doping increased by 12%(from 0.48 cm3 g-1 to 0.6 cm3 g-1)compared with the sample without HC treatment but with the same nitrogen doping.The specific surface area of micropores increased by 20.1%(from 1207 m2 g-1 to 1450 m2 g-1),and the microporosity increased from 30%to 42%.The introduction of melamine increased the microporosity and microporosity by HC treatment.The volume and specific surface area of micropores proved that HC combined with melamine had a great influence on the amount of micropores of PBC.Under the two-electrode system(6 M KOH),the specific capacitance of the SC of the "KOH(1:6)+HC+C3H6N6" sample at a current density of 1 A g-1 is 305 F g-1,which has the highest specific capacitance,as well as the highest energy density and excellent pore structure.After 5000 charge-discharge cycles(with a current density of 5 A g-1),the capacitance retention rate of the "KOH(1:6)+HC+C3H6N6" sample SC was as high as 100%,showing extremely excellent cycling characteristics.更多还原