【作者】 杨静；

【导师】 雷立旭；

【作者基本信息】 东南大学 ， 物理化学， 2020， 硕士

【摘要】 铅酸电池被发明到现在已有160多年,为世界工业化进程做出了卓越的贡献。因为使用安全,性价比高,生产工艺成熟,具有相对完善的回收体系,铅酸电池依旧在工业生产和日常生活中发挥着重要作用。近年来,随着人们活动半径的日渐加大,化石能源被大量使用,由此造成的环境问题日渐突出,电动助力车、混合动力和纯电动汽车产业应运而生,并在持续发展中。铅酸电池性价比高,一次投入少,因此深受普通百姓欢迎,生产销量多年来持续增长。以此同时,人们也对电池性能提出了更高的要求。与锂离子电池相比,铅酸电池能量密度低,循环寿命短,因此在普通乘用车中使用严重受限。相对而言,铅酸电池若用作可再生能源的固定式储能装置,则可以避免能量密度低的缺点,但大规模的使用必须解决一致性问题和循环寿命偏短的问题。多年来,人们致力于开发新的电极材料,使用各种添加剂来提高铅酸电池的能量密度。除此之外,虽然目前铅酸电池具有最完善的回收工艺,但是所使用的冶金工艺耗能大,过程中易产生铅尘和SO₂,具有高的污染风险。以上缺点使得铅酸电池行业的利润率低,士气低落。最近十余年来,我们实验室开展了铅酸电池循环生产新工艺研究,已确定了使废旧电池100%资源化的方法,且能生产结构和形貌都一致的硫酸铅、碱式硫酸铅和格栅合金,以及使用它们制造高性能高一致性的铅酸电池。但硫酸铅颗粒间的粘附力不如传统铅粉,硫酸铅电极活性物质在制造过程中易脱落,提高了工业化生产的难度。因此,我们希望通过使用有机聚合物作为粘结剂与碳材料混合制备导电胶并将其作为硫酸铅负极的添加剂来提高电极的机械性能和电化学性能。本研究主要成果如下:（1）导电胶的制备。固定导电剂碳材料的总量,改变粘结剂聚乙烯醇（PVA）和聚苯乙烯磺酸钠（PSS）的用量,混合均匀形成膏体,然后压制成导电胶薄片。干燥后,通过测定其电导率和LSV曲线来优化配方。结果发现,当粘结剂添加量分别为0.3%PVA+0.2%PSS、0.3%PVA+0.6%PSS、0.4%PVA+0.4%PSS、0.5%PVA+0.2%PSS时,制得的导电胶具有较高的电导率和析氢过电位。（2）电极制造工艺的确定。通过观察干燥后和化成后极板的电镜图,以及所得极板的放电性能,选出最佳的混料方式。结果发现,相对于方式1,首先将活性物质与导电剂干混,然后加入粘结剂混匀;和方式2,首先将粘结剂与导电剂混合,然后加入活性物质混匀;方式3,首先将粘结剂与活性物质混合,然后加入导电剂混匀为最优的混料方式。使用工业上常用的测试方法检测粘结剂对电极机械性能的影响,结果表明粘结剂可以有效提高极板的机械强度。（3）研究了导电胶中粘结剂含量对硫酸铅电极电化学性能的影响。将选出的四组导电胶作为添加剂,使用如上方式3混料制作硫酸铅电极。组装电池后,分别进行充放电循环测试、倍率测试和电极的电化学性能测试,并研究不同充放电阶段电极的结构形貌,结果发现,当粘结剂的添加量为0.5%PVA+0.2%PSS时,电极在电流密度为100 m A·g^-1,100%深度放电下可达到约110 m Ah·g^-1的稳定放电比容量,拥有约700圈的循环寿命。实验还发现,PSS的加入可以有效缩短电池的活化时间。没有使用PSS的电极通常需要约20圈循环才能达到稳定放电容量,但当PSS存在时,5～8圈即可达到较高的稳定放电比容量。（4）探究了使用PVA和PSS替代目前硫酸铅负极中添加的木质素磺酸钠的可行性。研究表明,使用粘结剂代替木质素磺酸钠的三个电极放电比容量均高于添加木质素磺酸钠的电极。在倍率测试中,添加粘结剂的电极表现出较好的循环稳定性。因此,添加粘结剂时,可以不使用木质素磺酸钠。更多还原

【Abstract】 Lead-acid batteries（LABs）with a history of more than 160 years have made outstanding contribution to the development of industrialization in the world.Nowadays,LABs still play an important role in the industrial production and daily life because of their advantages of safety,cost effectiveness,mature production technology,as well as relatively complete recycling system.In recent years,with the increasing radius of people’s activities,fossil energy is consumed in large qugntities,resulting environmental problems more prominent.The electric moped,hybrid and pure electric vehicle industries come into being.LABs are cost-effective,which are popular with ordinary people.Therefore,the production and sales of LABs have continued to increase over the years.However,people also put forward higher requirements for battery performance.Compared with lithium-ion batteries,LABs have low energy density and short cycle life,limiting the use of LABs in ordinary passenger vehicles.However,if the LABs are used as fixed energy storage devices for renewable energy,the disadvantange of low energy density can be avoided.Unfortunately,the problem of consistency and short cycle life have to be solved in the large-scale use.Over the years,people have been committed to improving the discharge capacity of LABs by developing new electrode materials and using various additives.Although the recycling of the spent LABs through the metallurgical process has been industrialized,it causes environmental concerns and high energy consumption.It is disappointing that the profit margin of the LABs industry is low caused by the above problems.In the past more than ten years,our team has been carrying out research on recycling procedures banning any metallurgical processes.The method of producing electrochemically active uniform lead sulfate or basic lead sulfate in a 100%resource-recycling manner from waste batteries and using them to manufacture high-performance and high-consistency LABs has been determined.However,the adhesion between PbSO₄ particles is not as good as traditional lead power,causing the active materials to fall off during the preparation process of PbSO₄ electrode,which increases the difficulty in preparing the electrode.In this paper,the conductive adhesive were prepared by using organic polymer polyvinyl alcohol（PVA）and sodium polystyrene sulfonate（PSS）mixed with carbon materials and used as an additive for lead sulfate negative electrode to improve the mechanical properties and capacity.The main rusults are as follows.（1）Preparation of conductive adhesive.The PVA and PSS as binders was added to the mixed carbon materials,following by making uniform paste.Finally,the paste was pressed into a conductive adhesive sheet.Four groups sheets with higher conductivity and hydrogen evolution potential were selected from the 9 groups of conductive adhesive formulations.The binders amounts of the four groups are:0.3%PVA+0.2%PSS、0.3%PVA+0.6%PSS、0.4%PVA+0.4%PSS、0.5%PVA+0.2%PSS（based on the quality of lead sulfate used in the negative plate,the same as below）;（2）Determination of electrode manufacturing process.The following three mixing methods were used.Method 1,Firstly,the active materials are mixed with the conductive agent,then the banders was added.Method 2,Firstly,the binders and the conductive agent were mixed,and then,the active materials was added.Method 3,Firstly,the binders and the active materials were mixed,and then,the conductive agent was added.The results of the SEM images of the electrodes,as well as discharge performance of the batteries show that Method 3 is best.The test method commonly used in the industry is used to detect the effect on the mechanical property of the electrode.The results show that the binders can effectively improve the mechanical strength of the PbSO₄ electrode.（3）The influence of conductive glue on the electrochemical performance of lead sulfate electrode.The four groups of conductive glue with excellent performance were selected as additives for lead sulfate electrode,and the best manufacturing method was used.When the amount of binders is 0.5%PVA+0.2%PSS,the electrode can reach a stable discharge specific capacity of about 110 m Ah·g^-1 and survives 700 cycles at 100%discharge depth at 100 m A×g^-1.It is worth mentioning that the addition of PSS can effectively shorten the activation time of batteries.It takes about 20 cycles to reach a stable capacity for electrodes without PSS.However,when PSS is present,the electrodes can achieve a higher stable discharge specific capacity only after 5～8 cycles.（4）To explore the feasibility of using binders PVA and PSS to replace the sodium lignosulfonate as an additive for PbSO₄ negative electrode.The results show that the capacity of the electrodes with binders are higher than that of the electrode with sodium lignosulfonate.In the rate test,the electrodes added binders have excellent cycle stability.Therefore,the sodium lignosulfonate can be replaced by the conductive glue as an additive for PbSO₄ negative electrode.更多还原