Battery Cell VSIP Charging for Fast Charge Without Lithium Plating
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Solution Overview
Problem
Current lithium-ion battery charging methods, such as CCCV and MSCC, are unable to charge batteries quickly without generating excess heat, causing lithium plating, reducing cycle life, and requiring complex cell balancing, limiting the driving range and charging time of electric vehicles.
Innovation Solution
The Voltage Staged Intermittent Pulse (VSIP) charging method applies multiple constant voltage stages with intermittent rest periods and pulse-like current, monitored for temperature and voltage limits, to increase discharge capacity beyond the rated capacity, allowing for fast charging without lithium plating and intrinsic cell balancing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If constant current and constant voltage charging methods are used, then charging simplicity is maintained, but charging time is extended beyond 60 minutes
Solution Approach 1:
The charging process is divided into multiple voltage stages (V1, V2, V3, etc.) with progressively increasing voltage levels. Each stage contains multiple intermittent pulse cycles, segmenting the continuous charging process into discrete controllable units. This segmentation allows the system to apply optimized charging parameters at each stage, achieving fast charging while maintaining safety.
Solution Approach 2:
Within each voltage stage, the charging current is applied in periodic pulse cycles rather than continuously. Each pulse cycle includes charging pulses followed by rest periods, creating a periodic action pattern. This periodic approach allows the battery to rest and dissipate heat between pulses, enabling faster charging rates without exceeding temperature limits or causing lithium plating.
2Productivity
If fast charging is implemented to reduce charging time, then charging speed is improved, but temperature increases causing overheating
Solution Approach 1:
The charging current is applied in periodic pulse cycles with intermittent rest periods. During rest periods, the current is reduced or stopped, allowing the battery to dissipate accumulated heat. This periodic action prevents continuous heat generation, maintaining temperature within safe limits while still achieving fast charging overall by utilizing higher current during the active pulse phases.
Solution Approach 2:
Before applying high current charging, the system preliminarily applies lower voltage stages to prepare the battery. The progressive voltage staging (V1→V2→V3) allows the battery to acclimate and prevents sudden thermal shock. This preliminary action at each voltage stage ensures the battery is ready for the next higher current level without excessive temperature rise.
3Productivity
If high charging current is applied to reduce charging time, then charging speed is improved, but lithium plating occurs reducing battery life
Solution Approach 1:
The periodic pulse charging with intermittent rest periods prevents continuous high current application that causes lithium plating. During rest periods, the battery chemistry stabilizes and allows proper lithium ion insertion without plating. This periodic action enables the use of higher charging currents during pulse phases while maintaining battery health and cycle life.
Solution Approach 2:
The progressive voltage staging applies preliminary lower voltage stages (V1, V2) before reaching higher voltage stages (V3, V4). This preliminary action allows the battery to gradually adapt to increasing current levels, preventing sudden conditions that would cause lithium plating. Each voltage stage prepares the battery for the next, ensuring safe and healthy fast charging.
4Manufacturing precision
If multiple voltage stages with intermittent pulses are applied, then charging control precision is improved, but device complexity increases
Solution Approach 1:
The charging system is segmented into standardized voltage stages and pulse cycles, each with predefined parameters. This segmentation creates a modular control structure where each stage and pulse cycle can be independently controlled and monitored. The modular nature simplifies implementation despite the multiple stages, as each unit follows the same control pattern.
Solution Approach 2:
The system controls charging by changing voltage parameters across discrete stages (V1, V2, V3, etc.) rather than continuous adjustment. Each stage has specific voltage and current parameters that are changed in a predetermined sequence. This parameter-based control approach simplifies the control logic compared to continuous control, as the system transitions between defined states rather than managing continuous variable adjustments.
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
VSIP enables full charging in under 60 minutes, maintains low temperatures, extends battery life, and increases energy density, eliminating the need for cell balancing and reducing lithium plating, while maintaining safety and long cycle life.
Implementation Method 1
a battery cell to be charged having a rated discharge capacity and provided with charge/discharge terminals
Data Source
AI summary
A method is used for increasing the discharge capacity (Qdisch) of a battery cell provided with charge/discharge terminals to which a charging voltage can be applied with a flowing charging current. The method involves applying a plurality of charge cycles to the battery cell, each of which comprises applying a plurality of constant voltage stages each comprising intermittent voltage plateaus, and monitoring current flow. The temperature of the battery cell is monitored and maintained under a predetermined limit temperature, and the charge cycles are performed until the discharge capacity reaches a predetermined target capacity greater than the rated capacity.