Vehicle Battery Electrode Split for Normal and Emergency Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy storage systems in vehicles do not effectively manage the distribution of electricity use between normal and emergency conditions, leading to insufficient travel distance on a single charge and inadequate charge-discharge cycle performance.
Innovation Solution
A vehicle-use energy storage apparatus with a negative electrode containing a first active material (carbon-based) for normal use and a second active material (higher oxidation potential and capacity) for emergency use, along with a control mechanism to signal the transition between these materials, ensuring sufficient normal use capacity and long-term durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single energy storage apparatus is used with a predetermined discharge lower limit voltage, then the device complexity is low, but the traveling distance on a one-time supply of electricity is insufficient and charge-discharge cycle performance deteriorates
Solution Approach 1:
The negative electrode is segmented into two distinct active materials: a first active material (graphite) for normal discharge reactions and a second active material (silicon or silicon compound) for emergency discharge reactions. This segmentation allows the system to optimize for both normal use duration and emergency capacity without compromising cycle performance, as each material operates in its optimal voltage range.
Solution Approach 2:
Different regions of the negative electrode are assigned different local qualities through the use of two distinct active materials with different discharge characteristics. The first active material provides stable, long-duration discharge for normal use, while the second active material provides high-capacity emergency discharge. This local differentiation resolves the contradiction by allowing each material to perform its specialized function optimally.
2Quantity of substance
If the discharge lower limit voltage is lowered to increase the amount of electricity, then the traveling distance increases, but the charge-discharge cycle performance deteriorates due to excessive discharge depth
Solution Approach 1:
The discharge process is segmented into normal discharge (using first active material within safe voltage limits) and emergency discharge (using second active material at lower voltages). This segmentation allows the system to access greater total electricity quantity while protecting the primary graphite material from excessive discharge depth that would harm cycle performance.
Solution Approach 2:
The second active material (silicon or silicon compound) acts as an intermediary that enables emergency discharge at lower voltages without directly compromising the first active material (graphite). This intermediary allows the system to access additional electricity quantity while the control unit ensures the primary material remains within its optimal discharge range for maintaining cycle performance.
3Productivity
If frequent power supply is performed to ensure sufficient traveling distance, then the traveling distance requirement is met, but the loss of time for frequent charging increases
Solution Approach 1:
The second active material is prepared in advance as a reserve capacity within the energy storage apparatus. This preliminary action ensures that when emergency discharge is needed, the additional electricity is already available without requiring frequent external charging interruptions, thus reducing time loss while maintaining sufficient traveling distance.
4Quantity of substance
If a high electric capacity is used to ensure sufficient traveling distance, then the traveling distance increases, but the device complexity and cost increase
Solution Approach 1:
Instead of uniformly increasing the capacity of a single active material throughout the electrode, the invention applies local quality by concentrating the second active material (silicon or silicon compound) in specific regions or as a composite with the first active material. This approach increases total electric capacity while maintaining a relatively simple overall apparatus structure, as the complexity is localized to the negative electrode composition rather than the entire system architecture.
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 system provides a sufficient amount of electricity for normal use while reserving capacity for emergencies, maintaining high charge-discharge cycle performance and extending the vehicle's usable lifespan.
Implementation Method 1
a main discharge reaction occurs in the first active material during a normal time
Implementation Method 2
a main discharge reaction occurs in the second active material during an emergency time
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
Provided are a vehicle-use energy storage apparatus, a vehicle-use discharge system, a discharge control method, and a vehicle-use energy storage device each capable of ensuring a sufficient amount of electricity as an amount of electricity used during a normal use time while ensuring an amount of electricity which is reserved as spare electricity, and possessing a sufficient charge-discharge cycle. According to an aspect of the present invention, there is provided a vehicle-use energy storage apparatus including an energy storage device having a negative electrode including a negative active material which contains: a first active material made of a carbon material; and a second active material having a higher oxidation potential than the carbon material and having a higher capacity per volume than the carbon material. In performing discharging of the energy storage device, a main discharge reaction occurs in the first active material during a normal time, and the main discharge reaction occurs in the second active material during an emergency time.