Ohmically Modulated Battery Temperature Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable batteries, particularly lithium-ion batteries, face performance issues at low temperatures and safety hazards at high temperatures, leading to inefficient power output and potential thermal runaway.
Innovation Solution
The development of an ohmically modulated rechargeable battery that can dynamically change its internal resistance levels with temperature, featuring a low resistance mode at normal temperatures and a high resistance mode at elevated or subzero temperatures, achieved through active or passive configurations, including resistor sheets and PTC materials, to enhance performance and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery operates at low temperatures, then the electrochemical kinetics and transport processes become sluggish, but the power performance and energy output are very low
Solution Approach 1:
The patent applies parameter changes by modifying the internal resistance of the battery through temperature-dependent materials (PTC or NTC). At low temperatures, the battery transitions to a high resistance state that prevents operation, while at elevated temperatures, it switches to a low resistance state that enables normal power performance. This dynamic parameter adjustment resolves the contradiction by making the battery unreliable only when necessary (extreme cold) while maintaining power performance in the operational range.
Solution Approach 2:
The battery employs self-service through intrinsic temperature-dependent resistance changes without requiring external control systems. The PTC or NTC materials automatically adjust the battery's resistance based on its own temperature, enabling the battery to self-regulate its operational state and prevent low-temperature operation without external intervention.
2Power
If the battery operates at high temperatures, then the internal heat generation increases, but the battery undergoes thermal runaway leading to safety hazards
Solution Approach 1:
The patent converts the harmful effect of high temperature into a beneficial safety mechanism. When the battery temperature rises to dangerous levels, the PTC material causes the resistance to increase sharply, which automatically limits the current and reduces heat generation. This transforms the thermal runaway risk into a self-protective mechanism that prevents catastrophic failure.
Solution Approach 2:
The battery implements preliminary anti-action by preparing a resistance increase mechanism that activates before thermal runaway occurs. The PTC or NTC materials are pre-positioned to automatically increase resistance when temperature reaches critical thresholds, preventing the harmful thermal runaway process before it can develop fully.
3Device complexity
If the battery uses a single internal resistance level, then the design is simple, but the battery cannot adapt to different temperature conditions
Solution Approach 1:
The patent applies dynamics by transitioning from a static single-resistance design to a dynamic multi-resistance system. The battery's internal resistance automatically changes based on temperature conditions, allowing the system to adapt its electrical characteristics in real-time. This dynamic behavior enables the battery to optimize performance and safety across different temperature ranges while adding minimal complexity through the use of intrinsic material properties.
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 solution improves battery performance at low temperatures by increasing power output and significantly reduces the risk of thermal runaway at high temperatures by limiting charge/discharge current and heat generation, thereby enhancing safety and efficiency.
Implementation Method 1
the battery's internal ohmic resistance can increase sharply so that maximum charge/discharge current possible is kept at low levels, which in turn reduces the internal heat generation substantially
Implementation Method 2
At low temperatures, especially subfreezing temperatures, rechargeable batteries, especially lithium-ion batteries, exhibit very low power performance and low energy due to sluggish electrochemical kinetics and transport processes occurring in the battery cell
Data Source
Figure 1
Figure 2A~2D
Figure 3A
AI summary
A rechargeable battery whose ohmic resistance is modulated according to temperature is disclosed.