Lithium Ion Battery Recovery via SOC Gradient Control

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Solution Overview

Problem

Existing methods for recovering lithium ion battery performance are not sufficiently effective, leading to decreased discharge capacity due to lithium dendrite formation on the negative electrode, especially in repeated charge/discharge cycles.

Innovation Solution

A recovery processing method involving a cycle of setting the State of Charge (SOC) to a first value where the SOC-voltage gradient is minimal during charging and then to a second value lower than the first during discharging, with the first value being 15% or less, to reduce lithium occlusion and facilitate dendrite decomposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional charge/discharge cycles are used to recover battery performance, then some performance recovery may occur, but the recovery effect is not sufficient and lithium dendrite formation continues

Engineering Contradiction:

Improvebattery performance recoveryVSAvoidlithium dendrite formation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by precisely controlling the SOC range (15% or less) and utilizing the minimum gradient point on the SOC-voltage curve to optimize the charge/discharge cycles. This specific parameter control enables effective lithium dendrite decomposition and battery performance recovery that conventional methods cannot achieve

Inventive Principle:

Principle #35Parameter changes

2Loss of substance

If the SOC is set to a very low value during charging, then lithium occlusion is reduced, but the charging efficiency and energy utilization may be compromised

Engineering Contradiction:

Improvelithium occlusionVSAvoidcharging efficiency

Core Design Contradiction:

Loss of substanceVSUse of energy by moving object

Solution Approach 1:

The patent replaces conventional charge/discharge mechanics with a specialized cycle method that operates at specific SOC points (minimum gradient point and 15% or less). This substitution creates a non-linear charge/discharge pattern that reduces lithium occlusion while maintaining energy efficiency through precise electrical parameter control

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This method effectively recovers lithium ion battery performance by reducing lithium dendrite formation, thereby extending the battery's lifespan and improving energy efficiency.

Implementation Method 1

a first process of setting an SOC of the lithium ion battery to a first value that is equal to or less than a value of the SOC where a gradient of an SOC-voltage curve is a minimum value through charging; and a second process of setting the SOC of the lithium ion battery to a second value smaller than the first value through discharging

Methodology Applied

Scientific EffectLithium ion intercalation and deintercalation:

Data Source

PatentUS20230207903A1Recovery processing method of lithium ion battery, charge/discharge device, and storage medium

Publication Date: 2023.06.29 HONDA MOTOR CO LTD

AI summary

A recovery processing method of a lithium ion battery includes repeating a cycle a plurality of times, and the cycle includes a first process of setting an SOC of the lithium ion battery to a first value that is equal to or less than a value of the SOC where a gradient of an SOC-voltage curve is a minimum value through charging, and a second process of setting the SOC of the lithium ion battery to a second value smaller than the first value through discharging.