Production process and link of lithium ion battery

China's energy storage net news: Lithium ion batteries form mainly has the positive and negative, nonaqueous electrolytes and diaphragm of four parts. With more on the market at present mainly for lithium-ion batteries lithium iron phosphate batteries and ternary lithium batteries, both the positive differences in raw materials, production process close to huge but process parameters need to change. If a full replacement for ternary lithium iron phosphate material, poor performance of the rectification of the old production line for battery manufacturers need to change the large area of production line equipment.

Lithium battery manufacturing process: in the former three working procedure, after accounted for nearly 35% / 30% / 35%

Lithium battery production process is complicated, the main production process mainly covers the electrode made of coated stage (front), batteries of synthetic winding injection liquid phase (middle), and turned to encapsulate the phase of testing (section), value (purchasing amount) accounted for about 35-40% () : (30 ~ 35) % (30 ~ 35) %.Differences mainly comes from the different equipment suppliers, the proportion of import/domestic differences, such as process flow, value deviation but overall than to have to meet the percentage.

Lithium electricity production in process of lithium electricity equipment mainly includes vacuum mixer, coating machine, rolling machine, etc.; The middle process mainly includes the die cutting machine, winding machine, lamination machine, liquid injection machine, etc.; After a process is included into machine, capacity testing equipment, the process of logistics automation, etc. In addition, the battery production need Pack automation equipment.

Li-ion battery in production process: sheet manufacturing battery core performance relationship

Lithium battery front-end process is the result of the lithium battery anode slice preparation is complete, the first process is stirring, the positive and negative solid-state batteries materials evenly mixed to join the solvent, through vacuum mixer to form a paste. Ingredients of the mixing is the basis of lithium electricity the follow-up process, high mixing quality is subsequent coating, rolling the basis of high quality to complete the process.

After coating and rolling process is cut, the coating for cutting process. During the process of cutting burr subsequent assembly, such as electrolyte injection program, even in the process of using the battery safe hidden trouble. So the front-end equipment in the process of producing lithium electricity, such as mixer, coating machine, rolling machine, slitting machine, is the core of the battery manufacturing machines, such as about the quality of the whole production line, therefore the front-end equipment value (amount) of the lithium electricity automatic production line of the highest proportion, about 35%.

Lithium electricity middle process, efficiency first, winding walked before lamination

Lithium battery manufacturing process, the middle process is mainly to complete the battery of forming, the main technological process includes production, plate coiling, die-cutting, batteries, winding forming and laminated molding and so on, is the current domestic equipment manufacturers more competitive, a field value is about 30% of lithium battery production line.

At present, power lithium battery manufacturing process of the main winding and laminated two kinds, the corresponding cell structure form for cylindrical and square, three kinds of soft package, cylindrical and square cells mainly adopts winding process, the soft package battery mainly USES the lamination process. Cylindrical mainly represented by 18650 and 26650 (Tesla developed 21700 batteries alone, are the industry promotion), the difference between the square and soft package is shell hard aluminum and aluminum composite membrane were used respectively to two kinds, mainly lamination process with soft package, aluminum shell is given priority to with winding process.

Soft package structure form is mainly for high-end digital market, higher margin per unit product, under the condition of same capacity, relative profit is higher than the aluminum battery. Due to aluminum battery easy to form scale effect, the product qualified rate and the cost is easy to control, at present the two in their areas all have substantial profits, the market for the foreseeable future, both are difficult to be replaced completely.

Because of the winding process can speed the high-speed production of batteries, and laminated technology can improve the speed is limited, so the current domestic power lithium battery mainly adopts the winding process is given priority to, so the shipments of winding machine is greater than the lamination machine at present.

Winding and lamination production before the corresponding production and die cutting plate. Production including the plate after cutting/welding, pole piece of dust, ear protection tape, plastic bags and winding or fixed-length cutting, the winding sheet was used for subsequent automatic winding, fixed-length cutting sheet was used for the subsequent semi-automatic winding; Die cutting plate is the plate after cutting and winding punching forming, lamination process for follow-up.

In li-ion battery assembly welding, league win, but, the mainstream of ever bright laser technology integration application manufacturer has involved, can satisfy the requirements, do not need to import.

Lithium electricity after a period of technological process, points RongHua Cheng is the core part

After lithium electricity production process mainly points capacity, into four working procedure, testing and packaging warehousing, production value of about 35%.To capacity and points as the period of the main part of the process, evaluate the activation in the shape of battery, due to battery charging and discharging test cycle is long, so the equipment has the highest value. Into a process's main role is to pour the batteries charging is activated after encapsulation, points for process is after the battery activation test battery capacity and other electrical parameters and grading. Into and let respectively by into a machine and machine is usually done by automation points RongHua Cheng system.

Li-ion battery Pack craft: the seemingly simple but needs to combine with systemic design

Power battery system is to many individual batteries by means of series and parallel connected battery, battery hardware such as a combination of power and thermal management system. Pack is the key of the power battery system production, design, application, and is connected to the upstream production and downstream vehicle batteries application core link, often put forward by batteries factory or plant design requirements, usually by the battery Pack factory complete, factory, or a third party.

Lithium battery Pack production line is relatively simple, the core process including feeding, bracket paste, welding, detection technology, the core equipment of the laser welding machine and all kinds of paste testing equipment. At present, each big lithium electricity equipment manufacturer in the field of automation integrated layout is less, and the coupling win laser: laser, because of the absolute superiority in the field of laser, laser equipment manufacturers, in the field of Pack equipment share is higher.

Now Pack production automation rate is relatively low, because the new energy vehicles single car sales is not big enough, the high cost of automatic production lines.

lithium iron phosphate and three yuan: energy density is not open around the topic, different materials need a full set of equipment investment

At present domestic mainstream power lithium battery cathode material divided into two big kinds, lithium iron phosphate and three yuan. Which is the most safe lithium iron phosphate lithium-ion battery cathode material, the cycle life is usually more than 2000 times, coupled with the industry mature and reduced the price and the technical threshold, makes many manufacturers for a variety of factors to consider using lithium iron phosphate batteries. However the lithium iron phosphate batteries are obvious defects in terms of energy density, lithium iron phosphate batteries currently leading BYD lithium iron phosphate monomer batteries energy density is 150 wh, BYD is expected to improve the energy density at the end of 2017 to 160 wh, theoretical energy density of lithium iron phosphate is difficult to more than 200 GWH.

The ternary polymer lithium battery is correct material use lithium cobalt nickel manganese acid lithium battery, nickel cobalt manganese actual ratio can be adjusted according to the specific needs. Because of ternary lithium batteries with higher energy density (the current era of Ningde power battery, such as first-class large ternary lithium battery energy density generally can reach 200 wh/kg - 220 wh/kg, the industry is expected to 2020, three yuan energy density batteries battery monomer will reach the level of 300 wh/kg), the passenger car market is turning to ternary lithium battery, and on the buses with higher security requirements, lithium iron phosphate is preferred. With the development of all electric passenger cars, the ternary lithium batteries are more and more important position.

The energy density and cost of the two materials have differences, different cars and car companies have different choices. Both in the production process is roughly same, the difference is mainly manifested in the use of material and the ratio of different diversity, specific process parameters, equipment not collinear production, and the simple transform the high cost of switching capacity (ternary strict material of vacuum dehumidification, lithium iron phosphate production line before the basic no dehumidification requirements), so many batteries factory in capacity planning and layout, equipment procurement, respectively.

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