Bipolar Battery Plate Graphite Composite
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Solution Overview
Problem
Bipolar lead-acid batteries face limitations in low discharge currents and energy density, with existing plates optimized for high discharge currents and weight reduction but lacking in performance for long-duration, low-power applications.
Innovation Solution
The development of bipolar battery plates with a graphite-based composite material coated with lead or lead alloy, featuring positive and negative active materials enhanced with carbon fibers and glass microspheres, along with carbon nanotubes, to increase conductivity and reaction surface area, replacing traditional lead grids and enhancing energy capacity and density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If traditional lead grids are used in bipolar battery plates, then mechanical strength and structural stability are maintained, but weight increases and energy density decreases
Solution Approach 1:
The patent employs composite materials consisting of lead alloy coated on graphite base material. The graphite provides lightweight structure while the lead alloy coating delivers necessary mechanical strength and electrochemical performance. This composite approach achieves weight reduction with maintained structural integrity
Solution Approach 2:
The patent modifies the composition parameters of the lead alloy coating (containing 5-15% tin and 0.5-2% calcium) to optimize both mechanical properties and electrochemical performance. By adjusting alloying elements and their concentrations, the coating achieves adequate strength while keeping the overall plate weight low
2Weight of moving object
If active material layers are made thinner to reduce plate weight, then weight decreases, but reaction surface area and energy capacity are reduced
Solution Approach 1:
The patent utilizes porous active material layers that provide high surface area to volume ratio. The porous structure increases the effective reaction surface area within the limited thickness, allowing adequate energy capacity while maintaining thin layers for weight reduction
Solution Approach 2:
The composite structure of graphite base material with lead alloy coating creates a high surface area substrate that supports thin active material layers. The graphite's inherent porosity and surface characteristics enable adequate reaction area without increasing layer thickness
3Productivity
If carbon fibers and glass microspheres are added to active materials to increase conductivity and reaction surface area, then energy density improves, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates carbon fibers and glass microspheres as additives within the active material composite. These additives enhance electrical conductivity and increase reaction surface area, improving energy density. The multi-component composite formulation achieves performance enhancement through material synergies
Solution Approach 2:
The patent optimizes the concentration parameters of additives (carbon fibers and glass microspheres) within the active material to achieve adequate conductivity and surface area without excessive complexity. By controlling additive content within specific ranges, performance is improved while manufacturing remains feasible
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 configuration results in a 60 Wh/kg energy density, a significant improvement over the 38 Wh/kg of traditional batteries, suitable for solar/photovoltaic systems by optimizing low discharge currents and maintaining mechanical strength and resistance.
Implementation Method 1
additives capable of enlarging the reaction surface area
Implementation Method 2
additives capable of enlarging the reaction surface area
Implementation Method 3
the positive plate or anode comprises lead oxide (PbO) as an active matter and, when electrically charged, it transforms the lead oxide into lead dioxide (PbO 2)
Implementation Method 4
the negative plate or cathode comprises, as an active matter, lead oxide (PbO) and an expanding agent, transforming the lead oxide into spongy lead (Pb)
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a plate (20), particularly for a bipolar battery (10), the plate (20) being of the type that comprises a base graphite material (2), a positive active material (3) applied to a first surface (4) of the base material (2) and a negative active material (5) applied to a second surface (6) of the base material (2) opposite the first surface (4), the positive active material (3) having a composition that comprises lead dioxide, conductive carbon fibers and glass microspheres, and the negative active material (5) having a composition that comprises spongy lead, graphite addi- tives and glass microspheres. One further describes a bipolar battery (10) formed by a plurality of plates (20), each plate (20) comprising a graphite base material (2), positive active material (3) applied to the first surface (4) of the base material (2) and negative active material (5) applied to a second surface (6) of the base material (2), opposite the first surface (4), the positive active material (3) of the plurality of plates (20) having a composition that comprises lead dioxide, conductive carbon fibers and glass microspheres, and the negative active material (5) of the plurality of plates (20) having a composition that comprises spongy lead, graphite additives and glass microspheres.