Analysis of the Manufacturing Process of Square Aluminum-Shelled Lithium-ion Batteries

As the core power unit of modern electronic devices and new energy systems, the performance and reliability of lithium-ion batteries highly depend on the precision of their manufacturing process. Especially in square structure systems, the matching aluminum shell for prismatic lithium-ion batteries plays a crucial supporting role in structural strength, heat dissipation, and overall consistency. The complete manufacturing process covers several core stages, including electrode preparation, cell assembly, liquid injection formation, aging and sorting, and packaging and shipping.

 

 

 

Electrode preparation is the starting point of lithium-ion battery production. Its core lies in achieving the stability and conductivity of the electrode structure through a reasonable material system and process control. Positive electrode materials, such as lithium iron phosphate and ternary materials, determine energy density and safety performance, while negative electrodes are usually based on graphite, balancing cycle stability and cost control.

 

During slurry preparation, active materials, conductive agents, and binders are uniformly dispersed through precise stirring to form a stable system. The coating process evenly covers the surface of the metal current collector with a slurry, and the compaction density and interfacial bonding strength are improved through drying and rolling processes. The uniformity at this stage directly affects the subsequent cell performance.

 

After electrode processing, the electrodes are slit according to the design dimensions, providing a basis for cell structure matching. Although this stage is a front-end process, it has a significant impact on subsequent assembly and adaptation with the Battery Aluminum Housing.

 

 

The cell assembly stage mainly completes the structural construction of the electrode system, including electrode tab welding, electrode and separator assembly, and housing encapsulation. Electrode tab welding typically uses laser welding technology to ensure low-resistance connections and high consistency.

 

In electrode assembly processes, winding and stacking are the two main paths. Winding is suitable for mass production, emphasizing tension and alignment accuracy; stacking is more advantageous in terms of space utilization. Regardless of the method used, the separator must ensure complete isolation of the positive and negative electrodes to prevent internal short circuits.

 

After structural assembly is completed, the cell is encapsulated in the housing. Prismatic cells typically utilize a prismatic cell case, which offers excellent mechanical strength and heat dissipation, while also facilitating module integration. In the power battery field, the New Energy Vehicle Aluminum Battery Case has become the mainstream structural form.

 

 

 

The electrolyte injection process is crucial for the battery to acquire electrochemical functionality. Strict drying treatment is required before injection to prevent moisture-induced side reactions. As an ion transport medium, the amount and wetting effect of the electrolyte directly affect the battery's internal resistance and capacity.

 

Subsequently, the formation stage, i.e., the first charge-discharge process, begins. During this process, a solid electrolyte interphase (SEI) film forms on the negative electrode surface. This film prevents continuous electrolyte decomposition while allowing lithium ions to pass through, making it a key structure for ensuring battery cycle stability.

 

At this stage, the compatibility between the cell and the lithium cell aluminum shell is particularly important, as its sealing performance directly affects electrolyte stability and long-term reliability.

 

 

Aging is a stabilization process in battery manufacturing, where internal reactions are brought to equilibrium under specific time and temperature conditions. This process helps optimize the SEI film structure, improve electrolyte wetting, and release early side reaction gases.

 

Different battery systems require different aging strategies. For example, lithium iron phosphate systems typically undergo medium- or high-temperature aging to improve consistency and cycle life. During this process, structural components such as aluminum alloy primamatic battery cases must possess good airtightness and dimensional stability to avoid deformation or leakage.

 

 

Capacity sorting and sorting involves testing key parameters such as capacity, voltage, and internal resistance to classify batteries. This process ensures high consistency within the same batch of batteries, thereby meeting the requirements of module or system-level applications.

 

For example, in power battery systems, inconsistent cells may lead to localized overcharging or over-discharging, affecting system lifespan and safety. Therefore, high-precision testing equipment and data management systems are crucial in this stage.

 

At the structural level, cell dimensions must be precisely matched to the prismatic cell aluminum shell to ensure the efficiency and stability of subsequent module assembly.
 

 

After completing all electrochemical and performance verifications, the battery enters the packaging stage. Packaging not only protects during transportation but also serves as a moisture barrier, anti-static agent, and shock absorber. The outer packaging must clearly label complete parameter information and safety warnings to meet transportation and usage regulations.

 

In practical applications, batteries are often delivered in module or pack form, for example, using a Battery Pack with an aluminum housing structure to improve overall strength and heat dissipation efficiency.

 

 

 

The manufacturing of prismatic aluminum-cased lithium-ion batteries is the result of a high degree of synergy between material systems, process control, and structural design. From electrode preparation to final shipment, every step directly affects the battery's safety, lifespan, and performance. A high-quality Deep Drawn Aluminum Battery Housing provides a reliable physical carrier for the cell and is an indispensable key component for achieving high-performance batteries.

 

 

We specialize in the R&D and manufacturing of high-precision battery structural components. Our products cover multi-specification aluminum shells for lithium-ion battery cells, power and energy storage housing systems, and customized pack aluminum housing solutions. Through advanced deep-drawing processes and a rigorous quality control system, we provide highly consistent and high-strength structural support for various applications, widely applicable to new energy vehicles, electrochemical energy storage, and high-end consumer electronics.