Multi-Chemistry Battery Pack Switching for Fast Charge and Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable energy storage systems (RESSs) in electrified powertrain systems experience degradation, efficiency decreases, slower charging and discharging performance, and reduced capacity, necessitating improved performance strategies.
Innovation Solution
A battery pack assembly with two cell sets of different battery chemistries (high energy density and high charging/discharging rate) is connected in series or parallel via switches, controlled by a DC-DC converter and a controller to optimize energy distribution and charging/discharging strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single battery chemistry is used in the energy storage system, then the system structure is simple, but the charging and discharging performance is limited and capacity is reduced
Solution Approach 1:
The battery pack is divided into multiple cell sets with different battery chemistries (e.g., lithium-ion and sodium-ion batteries). Each cell set can be independently controlled and connected to the load or charger through switches, allowing selective operation of different battery types based on charging/discharging rate requirements while maintaining manageable system complexity.
Solution Approach 2:
The system dynamically switches between different battery cell sets based on real-time operating conditions. The controller monitors state of charge, temperature, and power demands to determine which battery chemistry should be active, enabling adaptive optimization of charging and discharging performance without permanent structural complexity.
2Quantity of substance
If high energy density battery chemistry is used, then capacity is increased, but charging and discharging rate decreases
Solution Approach 1:
Different regions of the battery pack (cell sets) are assigned different battery chemistries optimized for specific functions. High energy density batteries (e.g., lithium-ion) provide capacity, while high power density batteries (e.g., sodium-ion) provide fast charging/discharging capability. The system selectively activates the appropriate cell set based on whether capacity or power is the priority.
Solution Approach 2:
The system uses a composite battery architecture combining multiple battery chemistries in one pack. This allows the system to leverage the complementary strengths of different battery technologies - the high capacity of lithium-ion and the high rate capability of sodium-ion - achieving overall performance that exceeds either chemistry alone.
3Power
If the battery system operates at high power output, then motive torque is increased, but efficiency decreases due to degradation
Solution Approach 1:
The controller dynamically selects which battery cell set to activate based on power demands and battery health status. When high power is needed, the system can draw from both cell sets in series. When degradation is detected or power demands are moderate, the system switches to a single cell set with lower stress, preserving efficiency and extending lifespan.
Solution Approach 2:
The system changes operational parameters by switching between different battery chemistries and connection configurations (series/parallel). This allows optimization of the operating point for each battery type, ensuring they operate within their optimal efficiency ranges while still meeting power demands. The DC-DC converter adjusts voltage and current parameters to match battery characteristics.
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
Enhances charging and discharging performance, increases capacity, and improves efficiency by leveraging the advantages of each battery chemistry under various conditions.
Implementation Method 1
A DC-DC converter is connected to the first cell set and to the second cell set and is configured to provide dynamic energy distribution between the first and second cell sets
Data Source
AI summary
An electrical system includes a battery pack assembly that includes a first cell set and a second cell set. The first cell set includes a first battery chemistry and the second cell set includes a second battery chemistry that is different than the first battery chemistry. Switches selectively connect the first cell set and the second cell set in series with battery connection terminals. A DC-DC converter provides dynamic energy distribution between the first and second cell sets. A controller controls the switches and the DC-DC converter. The controller is configured to determine an operating strategy and places the first cell set, the second cell set, or both the first and second cell sets in electrical communication with the battery connection terminals in response to the operating strategy of the battery pack assembly.