Lithium-Ion Battery Pack Charging Current Optimization for Fast Safe Charging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional lithium battery charging methods are inefficient, prone to overcurrent charging, and fail to minimize battery damage due to fixed parameters and lack of consideration for the battery's actual state, leading to slow charging speeds and low efficiency.

Innovation Solution

A multi-target simultaneous charging method for lithium battery packs that uses a charging weight coefficient to convert energy loss and current into a quadratic programming problem, solved using an interior point method and adaptive momentum gradient descent algorithm to optimize the charging current sequence, ensuring the shortest convergence and charging times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If constant current charging is used, then charging speed is improved, but battery damage increases due to overcurrent charging

Engineering Contradiction:
Improvecharging speedVSAvoidbattery damage
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic charging current adjustment by dividing charging into multiple stages with different current levels. The charging current is dynamically changed based on charging progress and battery state, transitioning from high current in early stages to lower current in later stages, thereby maintaining fast charging speed while preventing battery damage from excessive current

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes charging parameters (current magnitude and duration) across different charging stages. By adjusting current parameters dynamically - using higher current initially and reducing current as charging progresses - the system optimizes both charging speed and battery safety, resolving the contradiction between fast charging and battery protection

Inventive Principle:
Principle #35Parameter changes

2Reliability

If constant voltage charging is used, then battery safety is improved, but charging speed decreases

Engineering Contradiction:
Improvebattery safetyVSAvoidcharging speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent employs dynamic voltage adjustment across charging stages rather than maintaining constant voltage throughout. In early charging stages, higher voltage is applied to achieve faster charging, while voltage is reduced in later stages to ensure battery safety, thus dynamically balancing speed and reliability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The charging process is divided into periodic stages with different voltage and current characteristics. Each stage has specific parameter ranges that are periodically applied, allowing the system to achieve fast charging during safe periods while ensuring battery protection during critical periods

Inventive Principle:
Principle #19Periodic action

3Reliability

If multi-stage charging is used, then battery safety is improved, but charging time increases

Engineering Contradiction:
Improvebattery safetyVSAvoidcharging time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent optimizes the duration and parameter transitions of each charging stage dynamically. By carefully controlling the time spent in each stage and smoothly transitioning between stages, the system achieves comprehensive battery protection while minimizing total charging time, preventing excessive prolongation despite multiple stages

Inventive Principle:
Principle #15Dynamics

4Productivity

If charging current is increased, then charging efficiency is improved, but polarization phenomenon worsens

Engineering Contradiction:
Improvecharging efficiencyVSAvoidpolarization phenomenon
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic current adjustment that adapts to battery state changes. By increasing current when the battery can accept it (reducing polarization impact) and adjusting current based on real-time feedback, the system maximizes charging efficiency while managing polarization effects through dynamic control rather than fixed current

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS20230266392A1Multi-objective simultaneous charging method for lithium-ion battery packs
Publication Date: 2023.08.24 ZHEJIANG UNIV
  • US20230266392A1 patent drawing
  • US20230266392A1 patent drawing
  • US20230266392A1 patent drawing

AI summary

Disclosed in the present invention is a multi-target simultaneous charging method for a lithium battery pack: converting energy loss and charging current into a lithium battery pack charging cost model with a charging weight coefficient, and using an interior point method for solving and processing to acquire a preset charging current sequence; on the basis of the preset charging current sequence, calculating the charging time required when charging the lithium battery pack, and adjusting the charging weight coefficient in the lithium battery pack charging cost model by means of an adaptive momentum gradient descent algorithm to obtain the charging weight coefficient with the shortest charging time; using the charging weight coefficient to optimize the lithium battery pack charging cost model to acquire a new preset charging current sequence; and using the new preset charging current sequence to implement charging, thereby implementing optimized multi-target simultaneous charging of the lithium battery pack.