Li4Ti5O12 Anode Coated with Lithium Oxide for Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithium batteries using Li4Ti5O12 as an anode active material suffer from low conductivity, resulting in low initial efficiency, capacity per volume, and energy density, and metallic lithium anodes are prone to dendrite formation leading to short-circuits and explosions.
Innovation Solution
The anode active material Li4Ti5O12 is coated with lithium oxide, such as lithium niobate, to enhance intercalation and deintercalation of lithium ions, improving conductivity and efficiency, and is combined with a conductive material and binder on a collector to form an anode for lithium batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Li4Ti5O12 is used as anode active material, then safety is improved (no dendrites), but conductivity is worsened (low initial efficiency and energy density)
Solution Approach 1:
The patent creates a composite structure where Li4Ti5O12 particles are coated with conductive carbon material and further covered with a lithium-containing oxide layer. This multi-layer composite approach combines the safety benefits of Li4Ti5O12 with the conductivity enhancement from carbon and the electrochemical activity improvement from the lithium-containing oxide, resolving the contradiction between safety and conductivity
Solution Approach 2:
The patent modifies the surface properties of Li4Ti5O12 by coating it with lithium-containing oxides (such as LiNbO3, Li2SiO3, Li2TiO3) which change the surface electrochemical parameters. This surface modification increases the initial efficiency and energy density without compromising the bulk safety characteristics of Li4Ti5O12
2Stability of the object's composition
If Li4Ti5O12 is used as anode active material, then stability is improved, but capacity per volume is worsened (low energy density)
Solution Approach 1:
The patent applies local quality modification by coating only the surface of Li4Ti5O12 particles with lithium-containing oxides. The core Li4Ti5O12 maintains its stable bulk composition while the surface layer provides enhanced electrochemical activity and increased capacity per volume, resolving the contradiction between stability and energy density
3Power
If charge rate is increased, then power is improved, but capacity is worsened (capacity loss at high rates)
Solution Approach 1:
The lithium-containing oxide coating changes the surface electrochemical parameters to enable faster lithium ion transport kinetics. This allows the electrode to maintain higher capacity even at increased charge rates, resolving the contradiction between power and capacity retention
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 surface-treated anode achieves high initial efficiency, cyclic properties, and high-rate performance, maintaining capacity and efficiency even at increased charge rates, while avoiding the risks associated with metallic lithium anodes.
Implementation Method 1
lithium oxide that intercalates and/or deintercalates lithium ions into and from the lattice structure of Li4Ti5O12
Data Source
AI summary
An anode includes a collector; and an anode active material layer disposed on the collector comprises an anode active material, which is lithium oxide coated Li4Ti5O12, a conductive material, and a binder, wherein the lithium oxide intercalates and/or deintercalates lithium ions into and from the lattice structure of Li4Ti5O12. By coating the surface of the anode active material with lithium oxide, an anode including the surface-treated anode active material has a high capacity, high-rate properties, and a high initial efficiency.