摘要
随着现代社会的发展，人类对能源的需求正在逐步加剧，传统能源大多是不可再生能源，且会造成环境污染。而太阳能是一种取之不尽、用之不竭的绿色生态能源，硅太阳能电池是一种能将太阳能转变成电能而被人类利用的器件，实现利用太阳能的目的，具有十分广阔的应用和研究前景。硅电池在发电过程中生成的温度会对电池的应用造成巨大影响。通过分析电池的散热途径可以发现，提高组件自身的热导率可以达到提高电池散热的目的。位于组件下层的EVA胶膜由于对透光率没有要求，可以通过填充改性的方式提高下层EVA胶膜的热导率，实现提高电池散热速率的目的。因此，本文采用导热填料T-ZnOw、T-ZnOw/ZnO、T-ZnOw/AlN对EVA胶膜进行填充改性，以期制备出能够显著提高热导率，同时电绝缘性能、力学性能、热稳定性能、交联度能满足应用要求的EVA复合胶膜。
本文主要做了一下几方面的研究并取得以下结果：
一、研究了T-ZnOw单一填料，T-ZnOw/ZnO，T-ZnOw/AlN混杂填料填充EVA胶膜的导热效果，确定了混杂填料的最佳体积比。实验结果表明，体积比T-ZnOw/ZnO、T-ZnOw/AlN都是4:1时效果最佳。三种体系的复合胶膜随着填料含量的增加表现出相似的变化趋势，在体积含量为5%之前，复合胶膜热导率的变化不大，在5%到15%时，导热网络通路开始形成，热导率开始迅速增加。超过15%时，热导率的增幅又开始放缓。
二、研究了填料的表面处理对复合胶膜热导率的影响，采用质量分数为1.5%的KH570和硬脂酸分别对T-ZnOw、ZnO、AlN进行表面处理，结果不同的表面处理方式对复合胶膜热导率的影响不一，其中KH570处理T-ZnOw、AlN的效果好于硬脂酸；而硬脂酸处理ZnO的效果好于KH570。
三、研究了三种体系的填料含量对EVA复合胶膜体积电阻率的影响，结果三体系复合胶膜的体积电阻率的变化规律相似，在体积含量为5%之前，体积电阻率的变化不大，超过5%时，导电网络通路开始形成，体积电阻率开始迅速下降。总体而言，在填充量不超过15%时，复合胶膜的电绝缘性能仍然可以达到光伏封装材料应用要求。
四、研究了三体系的填料含量对EVA复合胶膜拉伸强度的影响，三种体系对复合胶膜的拉伸强度影响规律相似，都是先曾后减，在体积含量为10%时达到最大值，总体而言，在填料的体积含量不超过20%时，复合胶膜的拉伸强度可以满足光伏封装材料应用要求。
五、研究了填料的加入对EVA复合胶膜热稳定性能的影响，结果各体系填料都能显著提高胶膜的热稳定性能。
六、研究了复合胶膜的交联，确定了交联的实验条件：交联剂的用量为质量分数的1.5%，交联温度为150℃，交联时间为30min，交联压力为5Mp。研究了交联对复合胶膜热导率和体积电阻率的影响，结果表明，交联可以使热导率与体积电阻率小幅提高。实验还研究了三体系填料对复合胶膜交联度的影响，发现不同填料对EVA复合胶膜交联度的影响不一，具体表现为对引发剂的增强和减活效应，T-ZnOw和AlN对引发剂具有减活效应，而ZnO对交联剂却有增强效应。总体而言，在填料体积含量不超过15%时，交联度可以达到光伏封装用EVA胶膜的应用要求。
With the development of the world, human’s need to energy become more and more rigorous,traditional energy mostly belongs to nonrenewable resources, and usually leads to environmentalpollution; while solar energy has been in the limelight as a clean energy source that isinexhaustible and inexhaustible, crystalline silicon solar cells is an device that can tranceformsolar energy into electrical energy, to realize the purpose of the use of solar energy, has the verygood application prospects. while much quantity of heat produce as solar cells generateelectricity that leading to the temperature rise of the device, which will has a huge impact to thesolar cells, Through the analysis of the module cooling way, it can be found that powergeneration efficiency of silicon solar cells can be improved by enhancing thermal conductivity ofsolar module. ethylene vinyl acetate (EVA) copolymer located in the lower of the device has norequirement to light transmittance, If we can improve the thermal conductivity of the EVAcopolymer via filling thermal conductive filler, the cooling efficiency of device can be improved.So this paper take T-ZnOw T-ZnOw/ZnO T-ZnOw/AlN as thermal conductive filler to fill EVAcopolymer, As to prepare the copolymer that with high thermal conductivity, at the same timedielectric protecties, mechanical property, thermal stability, and degree of cross linking meetsrequirements.
This paper mainly studied on some aspects as follows:
(1) The thermal effect of EVA copolymer filled with T-ZnOw. hybrid system T-ZnOw/ZnO andT-ZnOw/AlN was studied, determine the best ratio of hybrid system, the result shows that thebest volume ratio was4:1, three system show the same variation trend with the increase of filler,before5%of volume content, Thermal conductivity increased slowly, between5%and15%,Thermal conductivity increases rapidly, after15%, the increase of thermal conductivity began toslow.
(2) The dependence of thermal conductivity of co-film of packing interface processing wasstudied, using the quality dosage of1.5%KH570and stearic acid to tread with T-ZnOw, ZnO, AlN, the result shows that different surface treatment appears different effect,T-ZnOw,AlNtreated with KH570was superior to stearic acid, while ZnO treated with stearic acid wassuperior to KH570.
(3) The dependence of volume resistivity of EVA co-film on three system’s volume content wasstudied, the result shows that three system show the same variation trend with the increase offiller, before5%of volume content, Volume resistivity change little, after5%, Volume resistivityslow rapidly, as a whole, before15%of volume content, dielectric protecties meet the pvpackaging materials application requirements.
(4) The dependence of tensile strength of EVA co-film on three system’s volume content wasstudied, the result shows that three system show the same variation trend that climb up and thendecline with the increase of filler, at the volume content of10%, tensile strength reach biggest, asa whole, before20%of volume content, tensile strength meets the pv packaging materialsapplication requirements.
(5) The dependence of thermal stability on the filler was studied, the result shows that eachsystem packing could improve the thermal stability
(6) crosslinking of EVA co-film was studied, the optimum experimental conditions weredetermined: the quality dosage was1.5%, Crosslinking temperature was150℃, crosslinkingtime was30min.crosslinking pressure was5MP. the dependence of thermal conductivity andvolume resistivity on crosslinking was studied, the result shows that thermal conductivity andvolume resistivity improved slightly after crosslinking; the dependence of degree of crosslinkingof three system’s volume content was studied at last, the result shows that defferent filler hasdifferent effect to the crosslinking,T-ZnOw and AlN reduce the activity of initiator, while ZnOincrease the activity, as a whole, before15%of volume content, degree of crosslinking meets thepv packaging materials application requirements.
引文
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