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Introduction of Lithium Battery Manufacturing Process and PACK Basic Knowledge
Release time:
2022-02-17 10:53
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锂电池在能量密度和功率密度的结合上具有无与伦比的优势,因而广泛应用于各种便携式电子用品、电力工具和电力/混合动力载具。下面贤集网小编为大家详细介绍锂电池制造工艺流程及PACK基础知识。
锂电池结构
不同结构形式、不同材料的工艺相似但装备需全新配置

锂离子电池构成主要由正极、负极、非水电解质和隔膜四部分组成。目前市场上采用较多的锂电池主要为磷酸铁锂电池和三元锂电池,二者正极原材料差异较大,生产工艺流程比较接近但工艺参数需变化巨大。若磷酸铁锂全面更换为三元材料,旧产线的整改效果不佳。对于电池厂家而言,需要对产线上的设备大面积进行更换。
锂电池制造工艺:前中后三道工序,占比接近35% /30%/35%
锂电池的生产工艺比较复杂,主要生产工艺流程主要涵盖电极制作的搅拌涂布阶段(前段)、电芯合成的卷绕注液阶段(中段),以及化成封装的包装检测阶段(后段),价值量(采购金额)占比约为(35~40%):(30~35)%:(30~35)%。差异主要来自于设备供应商不同、进口/国产比例差异等,工艺流程基本一致,价值量占比有偏差但总体符合该比例。
锂电生产前段工序对应的锂电设备主要包括真空搅拌机、涂布机、辊压机等;中段工序主要包括模切机、卷绕机、叠片机、注液机等;后段工序则包括化成机、分容检测设备、过程仓储物流自动化等。除此之外,电池组的生产还需要Pack自动化设备。

锂电前段生产工艺:极片制造关系电池核心性能
锂电池前端工艺的结果是将锂电池正负极片制备完成,其第一道工序是搅拌,即将正、负极固态电池材料混合均匀后加入溶剂,通过真空搅拌机搅拌成浆状。配料的搅拌是锂电后续工艺的基础,高质量搅拌是后续涂布、辊压工艺高质量完成的基础。
涂布和辊压工艺之后是分切,即对涂布进行分切工艺处理。如若分切过程中产生毛刺则后续装配、注电解液等程序、甚至是电池使用过程中出现安全隐患。因此锂电生产过程中的前端设备,如搅拌机、涂布机、辊压机、分条机等是电池制造的核心机器,关乎整条生产线的质量,因此前端设备的价值量(金额)占整条锂电自动化生产线的比例最高,约35%。

锂电中段工艺流程:效率先行,卷绕走在叠片之前
锂电池制造过程中,中段工艺主要是完成电池的成型,主要工艺流程包括制片、极片卷绕、模切、电芯卷绕成型和叠片成型等,是当前国内设备厂商竞争比较激烈的一个领域,占锂电池生产线价值量约30%。
目前动力锂电池的电芯制造工艺主要有卷绕和叠片两种,对应的电池结构形式主要为圆柱与方形、软包三种,圆柱和方形电池主要采用卷绕工艺生产,软包电池则主要采用叠片工艺。圆柱主要以18650和26650为代表(Tesla单独开发了21700电池、正在全行业推广),方形与软包的区别在于外壳分别采用硬铝壳和铝塑膜两种,其中软包主要以叠片工艺为主,铝壳则以卷绕工艺为主。
软包结构形式主要面向中高端数码市场,单位产品的利润率较高,在同等产能条件下,相对利润高于铝壳电池。由于铝壳电池易形成规模效应,产品合格率及成本易于控制,目前二者在各自市场领域均有可观的利润,在可以预见的未来,二者都很难被彻底取代。
由于卷绕工艺可以通过转速实现电芯的高速生产,而叠片技术所能提高的速度有限,因此目前国内动力锂电池主要采用卷绕工艺为主,因此卷绕机的出货量目前大于叠片机。

卷绕和叠片生产对应的前道工序为极片的制片和模切。制片包括对分切后的极片/极耳焊接、极片除尘、贴保护胶纸、极耳包胶和收卷或定长裁断,其中收卷极片用于后续的全自动卷绕,定长裁断极片用于后续的半自动卷绕;冲切极片是将分切后的极片卷绕冲切成型,用于后续的叠片工艺。

在锂电封装焊接方面,联赢、大族、光大的主流激光技术集成应用厂家均有所涉及,能够满足需求、无需进口。

锂电后段工艺流程:分容化成是核心环节
锂电后段生产工艺主要为分容、化成、检测和包装入库四道工序,占生产线价值量约35%。化成和分容作为后段工艺中最主要环节,对成型的电池进行激活检测,由于电池的充放电测试周期长,因此设备的价值量最高。化成工艺的主要作用在于将注液封装后的电芯充电进行活化,分容工艺则是在电池活化后测试电池容量及其他电性能参数并进行分级。化成和分容分别由化成机和分容机通常由自动化分容化成系统完成。
锂电Pack工艺:看似简单但需要与系统性设计结合
动力电池组系统是将众多单个的电芯通过串、并联的方式连接起来的电池组,综合了动力和热管理等电池硬件系统。Pack是动力电池系统生产、设计应用的关键,是连接上游电芯生产和下游整车的应用核心环节,通常设计需求由电芯厂或汽车厂提出,通常由电池厂、汽车厂或者第三方Pack厂完成。
锂电池Pack产线相对简单,核心工序包括上料、支架粘贴、电焊、检测等工艺,核心设备为激光焊接机以及各类粘贴检测设备。目前,各大锂电设备厂商在此领域的自动化集成布局较少,而大族激光、联赢激光等激光设备厂商由于在激光领域的绝对优势,在Pack设备领域占有率较高。
目前Pack生产的自动化比例相对较低,是因为目前的新能源车单款车销量都不够大,上自动化生产线的成本较高。

磷酸铁锂和三元:能量密度绕不开的话题,不同材料需要全套设备投资
目前国内主流动力锂电池的正极材料分为磷酸铁锂和三元两大种类。其中磷酸铁锂是目前最安全的锂离子电池正极材料,其循环寿命通常在2000次以上,再加上由于产业成熟而带来的价格和技术门槛的下降,使得很多厂商出于各种因素考虑都会采用磷酸铁锂电池。然而磷酸铁锂电池在能量密度方面则存在明显的缺陷,目前磷酸铁锂电池龙头比亚迪磷酸铁锂单体电芯能量密度为150Wh,2017年底比亚迪预计将能量密度提升到160Wh,理论上磷酸铁锂能量密度很难超过200Gwh。
三元聚合物锂电池是指正极材料使用镍钴锰酸锂的锂电池,镍钴锰的实际比例可以根据具体需要进行调整。由于三元锂电池具备更高的能量密度(目前宁德时代等动力电池一流大厂三元锂电池能量密度普遍能达到200Wh/kg-220Wh/kg,业内预计到2020年三元电池单体电芯能量密度将达到300Wh/kg的水平),乘用车市场开始转向三元锂电池,而在安全性要求更高的客车上,磷酸铁锂则更受青睐。随着全电动乘用车的发展,三元锂电池正在占据越来越重要的位置。
两种材料的能量密度和成本有差异,不同的汽车、不同的车企有不同的选择。二者在生产工艺流程上大致相同,区别主要体现在材料的使用和配比上不同、具体工艺参数差异较大,设备无法共线生产,且单纯改造切换产能的成本较高(三元材料对真空除湿等要求严格,之前的磷酸铁锂生产线基本没有除湿要求),因此多家电芯厂在产能规划中会同时布局、分别采购设备。

5分钟带你搞懂锂电池PACK基础知识
锂电池电芯组装成组的过程称为PACK,可以是单只电池,也可以是串并联的电池模组等。当下新国标大背景下,锂电池需求量越来越大,很多铅酸电池企业也纷纷推出锂电产品;其实锂电池PACK工艺不难,掌握这一技术自己可组装电池,而不再仅仅充当厂家“电池搬运工”的角色,利润和售后不再受制于人;掌握一门技术,有“锂”走遍天下。
PACK组成
PACK包括电池组、汇流排、软连接、保护板、外包装、输出(包括连接器),青稞纸、塑胶支架等辅助材料这几项共同组成PACK。
锂电池PACK实例
PACK的特点
①电池组PACK要求电池具有高度的一致性(容量、内阻、电压、放电曲线、寿命)。
②电池组PACK的循环寿命低于单只电池的循环寿命。
③在限定的条件下使用(包括充电、放电电流,充电方式,温度等)。
④锂电池组PACK成型后电池电压及容量有很大提高,必须加以保护,对其进行充电均衡、温度、电压及过流监测。
⑤电池组PACK必须达到设计需要的电压、容量要求。
PACK的方法
①串并组成:电池由单体电池通过并串联而成。并联增加容量,电压不变,串联后电压倍增,容量不变,如3.6V/10Ah电池由单只N18650/2Ah通过5并组成。先并后串:并联由于内阻的差异、散热不均等都会影响并联后电池循环寿命。但单个电池失效自动退出,除了容量降低,不影响并联后使用,并联工艺较严格。并联中某个单位电池短路时,造成并联电路电流非常大,通常加熔断保护技术避免。先串后并:根据整组电池容量先进行串联,如整组容量1/3,最后进行并联,降低了大容量电池组故障概率。
②电芯要求:根据自己设计要求选取对应电芯,并联及串联的电池要求种类一致、型号一致,容量、内阻、电压值差异不大于2%。一般情况下,电池通过并联串联组合后,容量损失2%—5%,电池数量越多,容量损失越多。不管是软包装电池还是圆柱电池,都需要多串组合,如果一致性差,影响电池容量,一组中容量最低的电池决定整组电池的容量。要求大电流放电性能。电机起步电流是正常工作电流的3倍,大电流放电才能提高电机动力性能。要求电池散热良好。电池数量较多,电池箱内部的电池温升不容易散出来,造成各电池间温度不均匀,放电特性不一,长久造成电池性能下降。生产工艺水平高。电池要能承受颠簸路面的振动冲击。对生产工艺尤其是点焊工艺要求高。焊接完毕后进行测试以防虚焊、脱焊。
③PACK的工艺:电池的PACK通过二种方式实现,一是通过激光焊接或超声波焊接或脉冲焊接,这是常用的焊接方法,优点是可靠性较好,但不易更换。二是通过弹性金属片接触,优点是不需焊接,电池更换容易,缺点是可能导致接触不良。
pack实例
充放电时间
充电时间(小时)=(电池容量Ah x充电系数)/充电电流A
放电倍率:电池的放电倍率用放电时间表示或者说以一定的放电电流放完额定容量所需的小时系数来表示。其中,放电倍率=额定容量/放电电
汇流排软连接的组装
PACK过程中会用到诸如镍片、铜铝复合汇流排、铜汇流排、总正总负汇流排、铝汇流排,也会用到铜软连接、铝软连接、铜箔软连接等。汇流排和软连接的加工质量需要从这几方面去评估。
①材料材质是否复合要求,汇流排材质不达标将会增加电阻率,尤其需要确认是否复合ROHS相关要求。
②关键尺寸加工是否到位。关键尺寸的超差有可能会在装配过程中导致高压器件之间的安全距离不够,并造成严重的安全隐患。
③软连接的硬区的结合力以及软区的应力吸收状况。
④实际加工的软连接及汇流排的过流能力是否达到设计标准,绝缘的热塑套管部位是否存在破损的情况。
以上就是关于锂电池制造工艺流程及PACK基础知识介绍,展望未来,锂电池能否满足人们对便携式蓄能装置的要求?若能从成本和性能上得到提高,锂电池的应用将会大大扩展,使很多新技术得以突破蓄能的瓶颈。对锂电池的研究有相当一部分是关于电极材料的。具备更高放电速率、更大电容量和足够高电压(仅对正极)的电极能显著提高锂电池的能量和功率密度,减小体积,降低成本。
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Which brand of Japanese Ni-MH battery is more stable and durable?
Under normal use of nickel-metal hydride batteries, generally speaking, the discharge time of power batteries with high capacity is long, and the discharge time of small capacity is short. However, there are two kinds of performance: stability and durability in the use effect. They become an important reference factor for positioning Ni-MH batteries, because if the stability and durability are insufficient, after encountering some abnormal use, Ni-MH batteries that show the battery life according to their capacity may have some variables, and even the high capacity is not durable due to insufficient stability. After testing five mainstream Japanese nickel-metal hydride battery brands, a Japanese media believes that Sanyo products are the most stable and durable.
Summary of Lithium-ion Battery Safety Test Items and Methods
Lithium-ion batteries and monolithic samples consisting of non-user replaceable batteries/lithium-ion batteries and their electronics. For non-user replaceable batteries, they should be installed in electronic products as a whole sample for the environmental safety test of lithium ion batteries in the standard. For non-user replaceable lithium ion batteries, they can be placed in electronic products as a whole sample, or the lithium ion battery can be taken out separately for the environmental safety test of lithium ion batteries in the standard. It is recommended to test as a whole sample first. As the test process may be deflated, smoke, fire or even explosion, it is necessary to take the necessary protective measures
Main battery type recycling methods and their recycling purposes
Different types of lithium batteries are widely used in different occasions, more scientific and economical recycling of waste batteries for reuse is a cause conducive to nature and human health. After hundreds of years of development, the basic recycling methods for major battery brands are the same in countries around the world. 1. dry batteries: alkaline manganese dry batteries and zinc manganese dry batteries, that is, generally referred to as carbon batteries and alkaline batteries. This type of battery is currently required to ban the use of mercury, so it is safe in life. For this reason, there is no requirement to recycle such batteries. Of course, those who are willing to recycle can engage in this aspect of business, and users do not have any in the garbage can.
Explosion-proof measures for battery and lithium battery
The safety of lithium-ion batteries has always been an important issue that plagues the industrialization of lithium batteries. The battery explosion accidents exposed in recent years are all caused by the use of lithium batteries. Compared with other types of batteries, this is determined by the special nature of lithium battery materials and processes. To this end, we should understand the knowledge of lithium battery explosion, we try to explain from the following three aspects. 1., the national standard stipulates that any part of the solid material within the battery is instantly discharged, and the distance that is pushed to the lithium battery above 25cm is called an explosion. The identification method in the experiment is: cover the experimental battery with a circular mesh so that the battery is located at the center of the circle, I .e. 25cm from any side of the mesh cover. If no solid part of the experiment passes through the mesh cover, it is proved that the battery has not exploded. Here, the "net" has a specific to show: the net wire adopts a soft aluminum wire with a diameter of 0.25mm, and the density of the net is 6~7/cm. 2. how to prevent lithium battery explosion All lithium battery explosions are caused by short circuit caused by battery heating, and the cause of short circuit and over charge, over discharge, positive and negative direct docking, electrolyte leakage and so on. Therefore, in the design of lithium batteries, the following points can be started: 1. It is forbidden to overcharge the battery to more than 4.2V; 2. It is forbidden to overcharge the battery to less than 2.75V; 3. An explosion-proof valve is installed on the metal shell; 4. Prevent short circuit in the process. The best way, of course, is to have a battery protection circuit board design. Although this will increase the manufacturing cost of lithium batteries, it is necessary for the safe use of lithium batteries. All regular lithium battery manufacturers can not avoid this design. 3. polymer lithium battery is the use of flexible packaging and polymer electrolyte made of a lithium battery products, under normal circumstances, the use of storage will not explode, unless man-made strong damage caused by its short circuit. In order to reduce the occurrence of explosion accidents, polymer lithium batteries are being used in more and more occasions. Although lithium batteries are still in the process of replacing other types of batteries, polymer lithium batteries have begun to replace ordinary lithium batteries in some areas.
Lithium Battery Market Analysis in 2020
The lithium battery industry market analysis report is an analysis of the lithium battery industry market size, market competition, regional market, market trends and the scope of attraction. It refers to the lithium battery industry market research and supply and demand forecasts, according to the market environment, competitiveness and competitors of the lithium battery industry products, analysis and judgment of the lithium battery industry products in a limited time whether there is a market, and what kind of marketing strategy to achieve sales goals or what kind of investment strategy to enter the lithium battery market. The main analysis points of the lithium battery market analysis report include: 1) lithium battery industry market supply analysis and market.