Graphene PPTC Heater Layout for Low-Temperature Battery Heating
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Solution Overview
Problem
Lithium-ion batteries used in electric vehicles experience performance degradation and safety hazards at sub-zero temperatures due to increased internal resistance, reduced conductivity, and risk of lithium plating, leading to decreased driving range and potential safety issues during cold weather charging.
Innovation Solution
A resistance heater using a polymer positive temperature coefficient (PPTC) material with a graphene filler component is integrated into the battery system to provide efficient heating, maintaining optimal operating temperatures and preventing overheating through self-regulating resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional heating elements are used to heat batteries at low temperatures, then heating function is provided, but energy consumption increases and heating efficiency decreases
Solution Approach 1:
The heating element uses a composite material consisting of PPTC polymer matrix combined with high-conductivity filler materials (graphene, carbon nanotubes, or metal particles). This composite structure provides both high electrical conductivity for efficient heating and automatic temperature regulation through PPTC's resistance increase at elevated temperatures, thereby reducing energy consumption while maintaining high heating efficiency.
Solution Approach 2:
The heating element exploits the temperature-dependent electrical resistance parameter of PPTC materials. At low temperatures, the material maintains low resistance for high power output and efficient heating. When the battery reaches optimal temperature, the PPTC's resistance automatically increases, reducing power consumption without requiring external control systems.
2Speed
If high power heating is applied to batteries at sub-zero temperatures, then heating speed increases, but temperature control precision deteriorates
Solution Approach 1:
The PPTC heating element provides inherent thermal feedback through its positive temperature coefficient characteristic. As the battery temperature rises during heating, the PPTC material's electrical resistance automatically increases, which naturally limits further temperature rise and prevents overheating. This self-regulating mechanism ensures both rapid heating at low temperatures and precise temperature control without external sensors or control circuits.
Solution Approach 2:
The heating element performs self-regulation of temperature without requiring external control systems. The PPTC material's intrinsic property of increasing resistance with temperature allows the heating element to automatically adjust its power output based on the battery's thermal state, providing both rapid heating and precise temperature control through self-service functionality.
3Reliability
If traditional heating elements are used, then heating function is provided, but device complexity increases
Solution Approach 1:
The PPTC heating element provides complete self-regulation functionality without requiring external temperature sensors, control circuits, or power management systems. The material's inherent positive temperature coefficient characteristic enables automatic power adjustment based on temperature, simplifying the overall system architecture while maintaining reliable heating function and preventing overheating.
Solution Approach 2:
The invention extracts and eliminates the need for complex external control systems by incorporating the temperature regulation function directly into the heating material itself. The PPTC material's intrinsic properties replace what would otherwise require separate sensors, controllers, and feedback circuits, thereby reducing device complexity while maintaining heating reliability.
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 PPTC heater ensures high power output with low energy consumption, quick heating, and reduced heat loss, maintaining battery performance and safety by regulating temperature effectively, thus enhancing the driving range and safety of electric vehicles in cold conditions.
Implementation Method 1
resistance heater may include a polymer positive temperature coefficient (PPTC) material, arranged in a heater body
Implementation Method 2
polymer positive temperature coefficient (PPTC) material
Data Source
AI summary
A resistance heater may include a polymer positive temperature coefficient (PPTC) material, arranged in a PPTC body defining a heater main surface. The PPTC material may include a polymer matrix, the polymer matrix defining the PPTC body, and a graphene filler component, disposed in the polymer matrix. The resistance heater may include an electrode assembly, comprising a first electrode and a second electrode arranged in contact with the heater body at two or more locations, a first lead, connected to the first electrode, and a second lead, connected to the second electrode. As such, the electrode assembly may define a current path between the first lead and the second lead, the current path comprising a first portion, extending along the heater main surface, and a second portion, extending through the heater body.