Battery Charging Control with Lithium Plating Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium ion batteries face safety risks due to lithium plating during fast charging, which can lead to internal short circuits and potentially explosive situations, and degraded battery cells in parallel connections pose safety hazards if not detected and separated.

Innovation Solution

A method for detecting lithium plating without a third electrode by monitoring battery voltage and comparing its slope with a reference slope, allowing for adjustment of charge current to prevent plating and safely disconnecting degraded battery cells from parallel connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If fast charging is performed with high charge current, then charging speed is improved, but lithium plating occurs on the anode surface causing safety risks

Engineering Contradiction:

Improvecharging speedVSAvoidbattery safety

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary detection of lithium plating conditions by monitoring voltage slope during charging. Before dangerous plating can occur, the controller detects the onset conditions (voltage slope becoming less than reference slope) and takes preventive action by adjusting charge current, thereby avoiding the harmful effect entirely

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors battery voltage and calculates the voltage slope during charging. This feedback information is used by the controller to detect lithium plating conditions and dynamically adjust the charge current, creating a closed-loop control system that balances charging speed with safety

Inventive Principle:

Principle #23Feedback

2Power

If parallel connected battery cells are used to support peak load, then power capacity is improved, but degraded cells create safety hazards if not detected

Engineering Contradiction:

Improvepower capacityVSAvoidsystem safety

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The system divides the battery system into individual cell segments, each with its own detection and control. By monitoring voltage slope of individual cells rather than the entire battery pack, the system can identify and isolate degraded cells while maintaining operation of healthy cells, thus preserving power capacity while ensuring safety

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The voltage slope measurement acts as an intermediary indicator that reveals the health status of individual battery cells. Rather than directly measuring cell degradation, the system uses voltage slope during charging as a proxy indicator to detect problematic cells and trigger appropriate isolation actions

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11159039B2Apparatus and method for battery charging with lithium plating detection and battery degradation detection and separation

Publication Date: 2021.10.26 INTEL CORP

AI summary

In some examples, an apparatus includes a controller to monitor voltage of a battery during constant current charging of the battery, and to detect lithium plating of the battery based on a rate of change of the monitored voltage of the battery during constant current charging of the battery. In some examples, a battery module includes a plurality of battery cells connected in parallel, and a controller to determine an impedance of each of the plurality of battery cells, and to disconnect one of the plurality of battery cells from the plurality of battery cells based on a relation of the impedance of the one of the plurality of battery cells with a threshold impedance.