Grooved LiCoO2 Cathode Structure for Faster Lithium-Ion Diffusion

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Solution Overview

Problem

Existing lithium ion batteries using LiCoO2 as a cathode active material face limitations in battery capacity and efficiency due to suboptimal ion conductivity and capacity variations based on crystal plane alignment.

Innovation Solution

The battery design incorporates a cathode layer with aligned crystal grains and strategically formed grooves perpendicular to the surface, enhancing lithium ion diffusion and ionic conductivity by aligning the side surfaces of the grooves with specific crystal directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LiCoO2 is used as cathode active material with conventional structure, then battery can be manufactured with standard process, but battery capacity and efficiency are limited due to suboptimal ion conductivity

Engineering Contradiction:

Improvebattery capacityVSAvoidcathode layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cathode layer is designed with locally varied crystal grain orientations, where side surfaces exposed by grooves have specific crystal directions (hk0) aligned for optimal lithium ion diffusion, while maintaining overall structural integrity. This local quality variation improves ion conductivity without requiring complete restructuring of the entire cathode material.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention introduces grooves that create additional surface area and expose side surfaces with specific crystal orientations that were previously inaccessible. This dimensional modification allows lithium ions to access high-conductivity pathways through the grooves, enhancing overall ion transport without changing the bulk material composition.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If grooves are formed in cathode layer to enhance ion diffusion, then ionic conductivity improves, but manufacturing process becomes more complex

Engineering Contradiction:

Improveionic conductivityVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The grooves are formed in the cathode layer before final assembly, allowing the crystal grains to be oriented during the groove formation process itself. This preliminary action ensures that when the cathode is assembled into the battery, the grooves are already in place to facilitate optimal ion diffusion pathways, eliminating the need for post-assembly modifications.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If crystal grains are aligned with specific crystal directions in grooves, then lithium ion diffusion is enhanced, but control and measurement of crystal orientation becomes more difficult

Engineering Contradiction:

Improvelithium ion diffusionVSAvoidcrystal direction alignment

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The invention utilizes X-ray diffraction (XRD) patterns as a 'fingerprint' to detect and measure crystal grain orientations. By analyzing the intensity ratios of specific diffraction peaks (I(101)+I(110))/I(003), the crystal orientation can be quantitatively assessed without requiring direct visual inspection of individual grain orientations, making the measurement process feasible and standardized.

Inventive Principle:

Principle #32Color changes

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 configuration increases battery capacity and efficiency by improving lithium ion diffusion and ionic conductivity, leading to enhanced charge/discharge characteristics and rate capability.

Implementation Method 1

enhancing lithium ion diffusion and ionic conductivity by aligning the side surfaces of the grooves with specific crystal directions

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

an electrolyte between the cathode layer and the anode layer

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS12211996B2Battery and method of manufacturing the same

Publication Date: 2025.01.28 SAMSUNG ELECTRONICS CO LTD

AI summary

A battery includes a cathode layer, a cathode current collector on the cathode layer, an anode layer on the cathode layer, an anode current collector on the anode layer, a separator between the cathode layer and the anode layer, and an electrolyte, wherein the cathode layer includes a plurality of crystal grains of a cathode active material and aligned in a first direction, and at least one groove formed in a direction perpendicular to an upper surface of the cathode layer that is in contact with the separator, and wherein a side surface of the cathode layer exposed by the at least one groove is aligned with a <101> crystal direction, a <hk0> crystal direction, wherein h and k are integers greater than or equal to 1, or a combination thereof, of the crystal grains of the cathode active material.