The electrode hot press bonding machine is a core equipment in membrane electrode manufacturing, widely used in new energy fields such as hydrogen fuel cells, flow energy storage batteries, and hydrogen production through electrolysis of water. It uses hot pressing technology to bond multiple layers of membrane electrode materials together, forming a structurally stable and reliable membrane electrode component. During the entire hot press bonding process, temperature and pressure are the two most critical process parameters that directly determine the bonding quality, product yield, and battery performance. So, what is the working principle of the electrode hot press bonding machine? How are temperature and pressure precisely controlled? This article combines the membrane electrode hot pressing bonding equipment of Shenzhen Baode Automation Precision Equipment Co., Ltd. to provide you with a detailed analysis.
1、 Basic working principle of electrode hot press bonding machine
The working principle of the electrode hot press bonding machine can be summarized as three stages: heating softening, pressure bonding, and pressure holding shaping.
Firstly, heating. Heat the upper and lower hot pressing plates to the set temperature to soften the membrane materials (such as proton exchange membranes and microporous layers), transforming them from a glassy state to a highly elastic state and possessing plasticity. Next is pressurization. By applying pressure through hydraulic or servo systems, the softened membrane material is embedded into the gaps of the porous electrode, releasing interlayer air and forming a tight physical contact, thereby reducing contact resistance. Finally, it is pressure holding and shaping. Maintain a set temperature and pressure for a period of time to fully bond the materials of each layer and form a stable composite interface; Some devices are also equipped with cooling systems to cool and shape under pressure, preventing rebound.
Taking Baode's 7-layer membrane electrode hot press bonding machine as an example, this equipment combines five layer membrane electrodes with two microporous layers on top and bottom to form a seven layer membrane electrode structure. The bonding error is controlled within 0.2mm, and the production cycle can reach more than 1.5 pieces/minute, fully reflecting the high efficiency and stability of the hot press bonding process in mass production.
2、 Temperature control: the "temperature" that determines the quality of bonding
Temperature is one of the most critical parameters in the hot press bonding process, which directly affects the bonding quality between the film and electrode and the stability of the material structure.
If the temperature is too low, the membrane material cannot be fully softened, resulting in poor contact between the catalytic layer and the membrane, insufficient bonding strength, and easy interlayer detachment; If the temperature is too high, it may cause excessive deformation or even thermal decomposition of the membrane material, which can damage the proton conductivity of the membrane. Therefore, temperature control must be precise, stable, and uniform.
Different membrane materials have different temperature requirements. The industry generally believes that the hot pressing temperature of membrane electrodes is generally set between 80 ℃ and 150 ℃, which needs to be determined according to the membrane material and electrode composition. The working temperature of the Baode 7-layer membrane electrode hot press bonding machine is set to no more than 150 ℃, which can cover the process window of most membrane electrode materials, ensuring bonding strength and avoiding damage to the membrane structure caused by high temperature.
In terms of control mode, hot press plates usually use electric heating and adopt zone independent temperature control design. The temperature of the upper and lower hot press plates can be set separately to meet the process requirements of different layer materials. The hot press plate is embedded with temperature sensors such as thermocouples, which can collect the surface temperature in real time and provide feedback to the control system; The control system adopts PID and other closed-loop algorithms to automatically adjust the heating power based on feedback signals, so that the temperature of the hot pressing plate is always stable near the set value, and the temperature difference is usually controlled within ± 2 ℃ to avoid local overheating or overcooling. At the same time, through reasonable layout of heating elements and design of hot pressing plate structure, the temperature distribution on the plate surface is ensured to be uniform, preventing fluctuations in bonding quality caused by uneven temperature.
3、 Pressure control: the "force" that determines the bonding strength
Pressure is a physical factor that promotes the tight bonding between the membrane and electrode layer, directly affecting the bonding strength, porosity, and contact resistance.
Sufficient pressure can embed the softened membrane material into the gaps of the porous electrode, expel air, increase contact area, and significantly reduce contact resistance. Insufficient pressure can lead to more interlayer gaps and insufficient compactness, affecting conductivity and cycle life; If the pressure is too high, it may cause excessive compaction of the electrode material structure and even damage the film layer.
The hot pressing pressure of membrane electrodes is generally set between 3MPa and 15MPa, depending on the product type and process requirements. The Baode 7-layer membrane electrode hot press bonding machine is equipped with a 2t pressure level press, coupled with a reasonable pressure distribution design, which can meet the strict requirements of membrane electrode bonding for pressure uniformity.
In terms of control mode, the equipment adopts a hydraulic system or servo electric cylinder to provide pressure, supports stepless pressure regulation, and can flexibly set pressure values according to process requirements. Real time monitoring of the actual pressure of the pressure plate through pressure sensors and feedback to the control system forms a closed-loop regulation to ensure that the pressure remains stable within the set range. At the same time, a gradual pressure application method is adopted, first removing interlayer bubbles at a lower pressure, and then gradually increasing to the target pressure to avoid material damage caused by sudden pressure changes and ensure the uniformity of the bonding interface. The upper and lower pressure plates maintain high parallelism and flatness, and are designed with even pressure distribution to ensure that all parts of the membrane electrode are uniformly stressed, avoiding uneven distribution of porosity caused by uneven stress.
4、 Collaborative control of temperature and pressure
In actual production, temperature and pressure do not act independently, but are coupled and coordinated with each other. Temperature affects the degree of softening and flowability of materials, while pressure determines the degree of compaction and embedding of materials. Both must be coordinated with time parameters to achieve the desired bonding effect.
When the temperature rises, the material softens, and the required pressure can be appropriately reduced; When the temperature is insufficient, higher pressure is needed to compensate. Therefore, the equipment needs to set and control the temperature, pressure, and time as a whole according to the process formula. The insulation and pressure holding time is generally controlled within a few tens of seconds to a few minutes. If the time is too short, the bonding is not sufficient, and if it is too long, it will affect the production cycle. Baode equipment can accurately control the parameters of each process stage by setting the stage pressure and stage time, balancing quality and production capacity. The device also supports storing and calling process parameters, and can directly call the corresponding formula when switching between different products, ensuring consistency between batches.
5、 Why choose professional electrode hot pressing bonding equipment
The quality of membrane electrode bonding directly determines the performance and lifespan of the battery, while manual or simple equipment is difficult to ensure pressure uniformity and temperature stability. Shenzhen Baode Automation Precision Equipment Co., Ltd. is deeply engaged in the fields of semiconductor vacuum bonding, perovskite photovoltaics, and new energy equipment. Its membrane electrode hot pressing bonding equipment has the following advantages:
In terms of high precision, the bonding error is controlled within 0.2mm, meeting the strict requirements of membrane electrodes for bonding accuracy; In terms of high stability, a closed-loop temperature control and pressure feedback system is adopted to ensure long-term stability of process parameters; In terms of high production capacity, the production cycle can reach 1.5 pieces/minute or more, which is suitable for mass production needs. In addition, Baode's 5-layer membrane electrode vacuum hot press bonding machine supports vacuum bonding, with a working vacuum degree not exceeding 60Pa, which can effectively eliminate bubbles and improve bonding quality; The equipment can also provide non-standard customized solutions based on customer product size and process requirements.
Conclusion
The working principle of the electrode hot press bonding machine is not complicated, but it requires high requirements for the design and control system of the equipment to achieve precise temperature, uniform pressure, and parameter coordination. As a fully automatic laminating machine manufacturer deeply involved in the field of new energy equipment, Baode always regards precise control of temperature and pressure as the core of equipment research and development. Temperature determines the bonding quality, pressure determines the bonding strength, and the two work together to produce membrane electrode products with stable performance and high yield. If you are looking for a reliable electrode hot press bonding machine, please contact Shenzhen Baode Automation Precision Equipment Co., Ltd. for professional equipment selection and process support.
