Lead Battery Plate Extrusion Grain Control
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Solution Overview
Problem
The manufacturing of lead or lead alloy plates for lead-acid batteries faces challenges such as intergranular corrosion and limited grain size control, which affect battery performance and service life, particularly due to the limitations of existing extrusion processes that restrict grain size and introduce tensile stress.
Innovation Solution
A method involving continuous extrusion of lead or lead alloy melts at temperatures 10-100°C below the melting point, followed by flattening at temperatures more than 230°C below the melting point, with controlled coolant supply to adjust grain size, allowing for the production of plates with desired grain sizes of 50-300 μm for anodes and 10-50 μm for cathodes, and minimizing draft rates to preserve the grain structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous extrusion is performed at temperatures close to the melting point followed by cold rolling with high draft rate, then the plate can be manufactured efficiently, but the grain size cannot be precisely controlled and intergranular corrosion occurs
Solution Approach 1:
The patent applies parameter changes by precisely controlling the extrusion temperature to be 10-100°C below the melting point of lead, and subsequently controlling the cooling rate during extrusion. This temperature parameter control enables precise grain size regulation (50-300 μm for anodes, 10-50 μm for cathodes) while maintaining manufacturing efficiency, resolving the contradiction between productivity and manufacturing precision.
2Productivity
If high draft rate is applied during cold rolling to reduce plate thickness, then productivity increases, but the grain structure deteriorates and intergranular corrosion increases
Solution Approach 1:
The patent applies preliminary action by establishing the desired grain structure during the extrusion process itself, before the flattening operation. By controlling extrusion temperature and cooling rate to pre-form the grain structure, the subsequent flattening can use minimal draft rate (0-10%) without compromising the grain structure, thus preventing intergranular corrosion while maintaining productivity.
3Manufacturing precision
If advanced temperature control during rolling is implemented to control grain size, then grain size precision improves, but device complexity and process complexity increase
Solution Approach 1:
The patent replaces the mechanical temperature control system during rolling with a thermal field control system during extrusion. By controlling the extrusion temperature (10-100°C below melting point) and cooling rate, the grain size is determined in the extrusion process itself, eliminating the need for complex temperature control systems during subsequent rolling operations.
4Manufacturing precision
If the extrusion temperature is reduced significantly below the melting point, then the grain size can be controlled, but the manufacturing process becomes less efficient and productivity decreases
Solution Approach 1:
The patent optimizes the extrusion temperature parameter to be within 10-100°C below the melting point of lead, which is the optimal range that simultaneously enables grain size control (through subsequent cooling) and maintains extrusion efficiency. This parameter optimization resolves the contradiction between manufacturing precision and productivity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables precise control of grain size during extrusion, reducing the need for advanced temperature control in rolling and minimizing draft rates, thereby enhancing the structural integrity and performance of lead-acid battery plates by suppressing intergranular corrosion and improving manufacturing flexibility.
Implementation Method 1
continuous extrusion of a melt of lead or lead alloy under temperatures lower by 10-100° C. than the melting point of lead, or the lead alloy, the extrudate being subsequently subjected to a flattening process under a temperature lower by more than at least 230° C. than the melting point of lead or the lead alloy
Implementation Method 2
The grain size of the lead or lead alloy may be controlled by cooling of the extrudate with coolants, such as for example air, inert gas, liquified gas, water, vapour, aerosol, cutting fluid, oil, combinations of such coolants, or no coolant at all
Data Source
AI summary
Disclosed are methods and a system for manufacturing a lead or lead alloy plate lattice for a lead-acid battery, comprising continuous extrusion of a melt of lead or lead alloy under temperatures lower by 10-100° C. than the melting point of lead, or the lead alloy, the extrudate being subsequently subjected to a flattening process under a temperature lower by more than at least 230° C. than the melting point of lead or the lead alloy, with a total draft rate less than 10%, and thereafter the extrudate may be processed so as to manufacture a plate lattice.