EV Battery Heating for Low-Temperature Fast Charging
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Solution Overview
Problem
Charging Li-based secondary batteries at low temperatures leads to lithium plating, which degrades battery performance and safety, necessitating longer charging times to maintain reliability.
Innovation Solution
An electric vehicle charging system that uses electromagnetic energy to heat the battery to a suitable temperature for fast charging, employing contactless energy transfer to convert electromagnetic energy into heat for localized heating before and during charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If charging power is increased to achieve fast charging, then charging speed is improved, but battery temperature control becomes difficult and safety deteriorates
Solution Approach 1:
The system performs preliminary heating of the battery using electromagnetic energy before initiating fast charging when the battery temperature is below the lower temperature limit. This preliminary action ensures the battery reaches the optimal temperature range (above 0°C and below 45°C) before high-power charging begins, preventing lithium plating and safety issues while enabling fast charging to proceed efficiently.
Solution Approach 2:
The system dynamically adjusts the battery temperature by controlling the magnitude of electromagnetic energy applied through contactless energy transfer. By changing the temperature parameter in real-time based on feedback from temperature sensors, the system maintains the battery within the safe operating range during fast charging, resolving the contradiction between high charging power and temperature control.
2Loss of time
If charging power is increased to achieve fast charging, then charging time is reduced, but lithium plating occurs and battery performance degrades
Solution Approach 1:
The system performs preliminary heating of the battery using electromagnetic energy before initiating fast charging when the battery temperature is below the lower temperature limit. This preliminary action ensures the battery reaches the optimal temperature range (above 0°C and below 45°C) before high-power charging begins, preventing lithium plating and safety issues while enabling fast charging to proceed efficiently.
Solution Approach 2:
The system continuously monitors battery temperature through temperature sensors and adjusts the electromagnetic energy input accordingly. During fast charging, if the temperature approaches the upper limit (45°C), the system reduces or stops electromagnetic heating to prevent overheating and lithium plating. This closed-loop feedback control maintains battery performance while enabling rapid charging.
3Temperature
If electromagnetic energy is applied to heat the battery, then battery temperature is improved for fast charging, but energy consumption increases
Solution Approach 1:
The battery itself serves as the heating element by converting electromagnetic energy directly into heat through its internal resistance. This self-heating mechanism eliminates the need for separate external heating devices and minimizes energy transfer losses, making the heating process more efficient. The electromagnetic energy is applied contactlessly and converted to heat where it is most needed - within the battery cells themselves.
Solution Approach 2:
The system performs preliminary heating of the battery using electromagnetic energy before initiating fast charging when the battery temperature is below the lower temperature limit. This preliminary action ensures the battery reaches the optimal temperature range (above 0°C and below 45°C) before high-power charging begins, preventing lithium plating and safety issues while enabling fast charging to proceed efficiently.
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
Ensures safe and efficient fast charging by maintaining the battery temperature within a safe range, reducing the risk of lithium plating and enhancing battery performance and reliability at low temperatures.
Implementation Method 1
an electromagnetic energy generator (118) configured to transfer, by contactless energy transfer means, electromagnetic energy (120) to an energy conversion module (166) of the electric vehicle (150)
Implementation Method 2
convert the electromagnetic energy to heat and heat the secondary battery (158) with the heat
Data Source
AI summary
The disclosed technology generally relates to charging a secondary battery of an electric vehicle and more particularly to thermal management of the secondary battery associated with charging. In one aspect, a method of charging a battery of an electric vehicle includes determining that a battery temperature of a secondary battery is below a predetermined lower temperature limit suitable for charging the secondary battery at a high charging power greater than 18 kW. The method additionally includes externally applying, by contactless energy transfer means, electromagnetic energy to an energy conversion module of the electric vehicle. The method additionally includes converting the electromagnetic energy to heat and heating the secondary battery to a temperature above the lower temperature limit. The method further includes charging the secondary battery at the high charging power while maintaining the battery temperature between the lower temperature limit and an upper temperature limit at least in part by controlling a magnitude of the electromagnetic energy transferred by the contactless energy transfer means. Aspects further relate to an electric vehicle charging station, a powering system for an electric vehicle and an electric vehicle charging system.