Atomic Layer Deposition Coating for Battery Electrode Particles

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Solution Overview

Problem

Lithium ion batteries face capacity loss due to the dissolution of transition metal ions in the electrolyte, especially in nano-particles, leading to reduced lithium intercalation sites and decomposition of solvents, which worsens with temperature and particle size reduction.

Innovation Solution

A method for covering nano-particles with a uniform, thin layer using atomic layer deposition in a fluidized bed reactor, employing a combination of reactants such as hydroxides, oxides, and metal alkyl compounds to form a protective monolayer without affecting electrochemical properties, allowing for increased pressure and vibration-assisted fluidization to ensure homogeneous coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If nano-particles are used to increase surface area and charge transfer, then charging speed and power performance are improved, but transition metal ion dissolution in electrolyte increases leading to capacity loss

Engineering Contradiction:

Improvecharging speedVSAvoidcapacity retention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A protective coating layer is introduced as an intermediary between the nano-particle surface and the electrolyte. This coating prevents direct contact between transition metal ions and the electrolyte, thereby eliminating dissolution while preserving the high surface area and charge transfer benefits of nano-particles.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A thin film coating is applied to the nano-particle surface to provide protection against ion dissolution. The coating is sufficiently thin to maintain the high surface area-to-volume ratio and charge transfer characteristics of nano-particles, while being sufficiently continuous to prevent harmful dissolution reactions.

Inventive Principle:

Principle #30Flexible shells and thin films

2Speed

If particle size is reduced to enhance lithium diffusion, then power performance increases, but dissolution of transition metal ions worsens

Engineering Contradiction:

Improvelithium diffusion rateVSAvoidion dissolution

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The protective coating acts as an intermediary barrier that allows the nano-particle structure to maintain its small size for fast lithium diffusion while preventing the harmful dissolution of transition metal ions into the electrolyte.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A thin protective film is applied to the surface of small nano-particles, enabling them to maintain high lithium diffusion rates due to their small size while the film prevents transition metal ion dissolution into the electrolyte.

Inventive Principle:

Principle #30Flexible shells and thin films

3Power

If high voltage positive electrode materials are used to compensate for anode potential, then battery output voltage increases, but dissolution of Mn-ions and solvent decomposition increase

Engineering Contradiction:

Improvebattery output voltageVSAvoidmaterial dissolution

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The protective coating serves as an intermediary layer between the high voltage cathode material and the electrolyte, preventing direct harmful interactions while allowing the high voltage material to deliver its full electrochemical performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A thin protective coating is applied to high voltage cathode materials to prevent Mn-ion dissolution and solvent decomposition, enabling these materials to operate at their high potentials without suffering from stability issues.

Inventive Principle:

Principle #30Flexible shells and thin films

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

The method significantly increases the lifetime of batteries by preventing transition metal ion dissolution, maintaining electrochemical performance, and ensuring consistent quality by providing a homogeneous nano-layer on nano-particles, even at high temperatures.

Implementation Method 1

a method for covering said particles with a uniform, thin layer using atomic layer deposition in a fluidized bed reactor

Methodology Applied

Scientific EffectFluidization: Fluidisation

Implementation Method 2

covering particles having a diameter of maximally 60 μm by means of atomic layer deposition

Methodology Applied

Scientific EffectAtomic layer deposition: Chemical Vapour Deposition

Data Source

PatentUS11024833B2Method for covering particles, especially a battery electrode material particles, and particles obtained with such method and a battery comprising such particle

Publication Date: 2021.06.01 FORGE NANO INC

AI summary

Described here is a powder comprising a plurality of lithium-containing particles having a dry, uniform protective layer, wherein the protective layer of the particles is obtained by a sequential vapor phase reaction or adsorption process. Also described is a battery comprising an anode layer and a cathode layer, wherein the cathode layer comprises lithium metal oxide or a lithium metal phosphate, wherein the metal comprises at least one of Nickel, Manganese, Cobalt, Iron, Titanium, and/or Manganese, wherein the cathode particles have a dry, uniform protective layer, and wherein the anode layer comprises lithium titanium oxide particles.