In lithium battery custom processing, shock-resistant and drop-proof structural design is a core aspect of ensuring battery safety. It requires comprehensive design across multiple dimensions, including material selection, structural layout, cushioning mechanisms, fixing methods, heat dissipation optimization, sealing protection, and dynamic monitoring, to form a systematic protection solution.
Material selection is fundamental to shock and drop resistance. The outer shell material must balance strength and toughness; aluminum alloys are commonly chosen due to their high strength and corrosion resistance, while stainless steel is suitable for extreme environments. Composite materials such as glass fiber reinforced plastics, through the synergistic effect of fibers and resins, improve impact resistance while maintaining lightweight. Internal electrode materials must possess flexibility; graphite, due to its layered structure, is less prone to breakage during vibration, and lithium cobalt oxide, through nano-modification, enhances structural stability. The electrolyte must employ a gel or solid-state design to prevent leakage or delamination of the liquid electrolyte during vibration.
The structural layout needs to be optimized using biomimetic principles. The honeycomb frame structure disperses impact force, and its hexagonal units absorb energy through deformation, while reducing overall weight. The battery pack employs a layered design, independently encapsulating the cells, circuit boards, and buffer layers to prevent localized impacts from spreading throughout the system. For multi-cell combinations, a "田" (field) pattern is used, with each cell connected by a central support pillar to minimize relative displacement.
The buffering mechanism is crucial for shock and drop resistance. Lithium battery custom processing fills the space between the cells and the casing with silicone or polyurethane foam; these materials dissipate energy through the stretching and compression of molecular chains. For high-vibration scenarios, a spring damping system can be embedded; the spring stiffness must be matched to the cell weight and vibration frequency to avoid resonance. Some designs utilize magnetorheological fluid dampers, adjusting the liquid viscosity through a magnetic field to achieve dynamic damping control.
The fixing method must ensure no relative movement between the cells and structural components. When using a snap-fit fixing method, elastic grooves should be installed around the battery cell, with a groove depth exceeding 10% of the cell thickness to prevent dislodgement. For cylindrical cells, a spiral locking structure can be designed, where rotating the outer shell causes the internal threads to engage with the outer wall of the cell. Rubber pressure blocks should be added to the ends of the cells, utilizing their elastic deformation to secure the cell while preventing direct metal-to-metal contact that could lead to short circuits.
Heat dissipation optimization and vibration-resistant design must be coordinated. Heat dissipation channels should be embedded in the cushioning material, with streamlined cross-sections to reduce air resistance. For high-power batteries, an integrated design of the liquid cooling plate and cushioning structure can be used, with micro-protrusions on the surface of the liquid cooling plate to enhance structural strength and increase the heat dissipation area. Phase change materials, such as paraffin-based composites, can be filled between the cells to control temperature through heat absorption during melting, while their rigidity in the solid state also aids in vibration resistance.
Sealing and protection must prevent structural failure caused by vibration. Laser welding is used at the seams of the outer casing, and the weld width must be controlled within 0.5mm to avoid stress concentration. O-rings are added between the cover and the casing; the cross-section of the O-rings must be selected according to the pressure rating—fluororubber for high-pressure scenarios and silicone rubber for low-pressure scenarios. For batteries requiring frequent disassembly, quick-release structures, such as spring-loaded latches, are designed to ensure sealing even after repeated vibrations.
Dynamic monitoring extends shock and drop resistance. An accelerometer is integrated into the battery management system (BMS) to monitor vibration acceleration in real time. When the acceleration exceeds a threshold, a protection mechanism is triggered, such as reducing output power or disconnecting the circuit. Algorithms analyze vibration frequency and direction to predict potential damage risks and adjust charging and discharging strategies in advance. Vibration data is recorded and uploaded to the cloud, providing a basis for structural optimization and forming a closed-loop design process.
