PIT Electrode Materials for Battery Pressure and Stress Relief
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Solution Overview
Problem
Existing battery technologies face performance and safety hazards due to excess internal pressure fluctuations during charging and discharging, which can lead to mechanical stress, degradation, and potential safety risks such as fires and explosions, particularly in metal ion batteries like lithium ion batteries.
Innovation Solution
Incorporation of pressure induced transition (PIT) materials in battery cells that respond to internal pressure changes by undergoing phase transitions, such as contraction, amorphization, or polymerization, to relieve mechanical stress and enhance conductivity, thereby stabilizing the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If electrode active material undergoes volume expansion during charging, then capacity is improved, but mechanical stress and internal pressure increase causing safety hazards
Solution Approach 1:
The patent incorporates pressure-induced transition (PIT) materials that undergo phase transitions (contraction, amorphization, or polymerization) in response to internal pressure changes during charging and discharging. These phase transitions allow the material to accommodate volume expansion of the electrode active material, relieve mechanical stress, and maintain structural integrity, thereby enabling high capacity while mitigating safety hazards.
Solution Approach 2:
The patent uses composite electrodes comprising both electrode active material and pressure-induced transition (PIT) material. This composite structure allows the PIT material to provide mechanical stress relief and volume accommodation while the active material delivers electrochemical capacity, resolving the contradiction between capacity improvement and mechanical stress reduction.
2Reliability
If internal pressure fluctuations are accommodated, then safety is improved, but electrical conductivity may deteriorate
Solution Approach 1:
The PIT materials undergo pressure-induced phase transitions that simultaneously achieve safety improvement and conductivity maintenance. The phase transitions (contraction, amorphization, or polymerization) accommodate internal pressure fluctuations to improve safety, while the resulting structural changes in the PIT material enhance or maintain electrical conductivity, preventing energy loss.
Solution Approach 2:
The patent exploits parameter changes in the PIT material (volume contraction, bandgap reduction, polymerization) in response to pressure changes. These parameter changes allow the material to adapt its properties dynamically: contracting to relieve mechanical stress for safety, while simultaneously reducing bandgap or forming conductive networks to maintain electrical conductivity.
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
The PIT materials effectively mitigate mechanical stress and improve electrical conductivity, extending cycle life and safety profiles of battery cells by accommodating volume changes and maintaining electrical contact across a broader temperature range.
Implementation Method 1
the pressure induced transition (PIT) material undergoes a transition in response to a change in an internal pressure of the battery cell caused by a change in a volume of the electrode active material during a charging and/or a discharging of the battery cell
Implementation Method 2
the transition includes a contraction in a volume of the pressure induced transition (PIT) material in response to an increase in the internal pressure of the battery cell caused by an expansion of the electrode active material. The contraction in the volume of the pressure indued transition (PIT) material relieves a mechanical stress imposed against the electrode active material
Implementation Method 3
the transition include an amorphization of the pressure induced transition (PIT) material from a crystalline solid to an amorphous or glass-like structure lacking long-range order that plastically deforms to accommodate an expansion of the electrode active material
Implementation Method 4
the transition includes a polymerization of the pressure induced transition (PIT) material to form a rigid, cross-linked polymer network in response to an increase in the internal pressure of the battery cell caused by an expansion of the electrode active material. The rigid, cross-linked polymer network limits further expansion of the electrode material
Implementation Method 5
the transition includes a reduction in a bandgap of the pressure induced transition (PIT) material in response to an increase in the internal pressure of the battery cell caused by an expansion of the electrode active material. The reduction in the bandgap of the pressure induced transition (PIT) material increases a conductivity of the second electrode
Data Source
AI summary
A battery cell may incorporate a pressure induced transition (PIT) material that undergoes a transition in response to changes in the internal pressure of the battery cell caused by the changes in the volume of the electrode in the battery cell that occur during the charging and discharging of the battery cell. The transition may include transformations that relieves the mechanical stress arising from the change in internal pressure as well as transformations that enhance the performance of the electrode. For example, the transition may include a phase change that manifests as a contraction in volume to accommodate the expansion of the electrode. This transition may also manifest as a reduction in bandgap to enhance the conductivity of the electrode. In some cases, the pressure induced transition (PIT) material may transition to provide a mechanical reinforcement of the electrode, thus limiting further changes in the volume of the electrode.