Binder-Free 3D Lithium Accumulator Electrodes
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Solution Overview
Problem
Lithium accumulators with 3D electrodes face challenges in reducing charging and discharging periods while maintaining high capacity, and existing production methods are complex and inefficient.
Innovation Solution
The lithium accumulator design features electrodes pressed directly onto perforated metal current collectors without organic binders, using a spatially distributed electron conductive component and active materials, with a separator made from pyrolyzed products or ceramic fibers, allowing for press-compacting and rolling production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If 3D electrodes are used to achieve high volumetric capacity, then the capacity is improved, but the charging and discharging periods increase
Solution Approach 1:
The patent transitions from traditional 2D planar electrodes to 3D spatially distributed electrode structures. The electrodes are formed by pressing active material into a three-dimensional configuration with interconnected pores, allowing lithium ions to access active material throughout the volume rather than just at the surface, thereby achieving high volumetric capacity while maintaining short ion transport paths
Solution Approach 2:
The patent employs porous electrode structures with controlled porosity (30-70%) formed by pressing active material containing inert particles that create interconnected void spaces. These pores allow efficient electrolyte penetration and lithium ion transport throughout the 3D electrode volume, enabling both high capacity and fast charging/discharging rates
2Stability of the object's composition
If organic binders are used in electrode production, then the electrode structure is stabilized, but the charging period increases and capacity decreases
Solution Approach 1:
The patent completely removes organic binders from the electrode composition. Instead of using binder materials to hold the electrode structure together, the invention relies on the mechanical interlocking of pressed active material particles and the formation of a binder-free structure where conductive carbon and active material are directly compressed into the desired 3D configuration, eliminating the charging time penalty associated with organic binders
Solution Approach 2:
The patent creates a composite electrode structure consisting of active material particles mixed with conductive carbon and inert particles that form the 3D porous framework. This composite approach eliminates the need for separate binder materials while maintaining structural integrity through the interconnected particle network and pressing process
3Strength
If frames are used to hold 3D electrodes, then the electrode structure is supported, but the volume and weight of the accumulator increase
Solution Approach 1:
The patent eliminates the frame structure entirely. The 3D electrodes are directly pressed and stacked without requiring external metal frames for support. The electrodes maintain their structural integrity through the compressed particle network and are held in place by the stacking arrangement and pressure applied during assembly, removing the dead weight of frames from the accumulator
Solution Approach 2:
The patent merges the electrode active material with the structural support function. The same pressed active material that provides electrochemical function also forms the load-bearing structure, eliminating the need for separate frame components. The electrodes are directly stacked and compressed to provide both functional and structural roles
4Strength
If frames are used to hold 3D electrodes, then the electrode structure is supported, but the active area decreases
Solution Approach 1:
The patent removes frames that would otherwise occupy space and block active areas. By using a frameless design where electrodes are directly pressed and stacked, the entire surface area of each electrode remains electrochemically active, as there are no frame structures to obstruct electrolyte access or reduce the effective area for lithium ion exchange
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 design reduces charging and discharging times, enhances lithium ion mobility, and achieves high volume capacity with improved safety and mechanical resistance, while simplifying the production process.
Implementation Method 1
a separator made from pyrolyzed products or ceramic fibers
Implementation Method 2
current collectors made of a perforated metal strip in the form of metal network, expanded metal or perforated metallic foil
Implementation Method 3
each electrode, free of organic binders is pressed down on both sides of the current collector
Data Source
Figure 1~2
Figure 3~3a
Figure 4~5
AI summary
A lithium accumulator with a housing comprising at least one cell with two electrodes (2a, 2b) provided with current collectors (3a, 3b) and separated by a separator (4) wherein each electrode (2a, 2b), free of organic binders, is pressed down onto both sides of the current collector (3a, 3b) made of a perforated metal strip in the form of metal network, expanded meal or perforated metallic foil. The minimum thickness of the electrodes (2a, 2b) is three times the thickness of the perforated metal strip (3a, 3b).