Prelithiated Anode for Lithium Ion Battery Formation Loss
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Solution Overview
Problem
Lithium ion batteries face significant formation loss during the first charging cycle, leading to increased costs and demand for expensive and toxic metals, as they require overdimensioning of cathode active materials and a complex, costly formation process.
Innovation Solution
A lithium ion battery with a composite cathode active material and a prelithiated anode active material, where the anode is preloaded with lithium before assembly, allowing the battery to be ready for use immediately, reducing the need for a precharge step and simplifying production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cathode active material is overdimensioned to compensate for formation loss, then the desired nominal capacity is achieved, but the production costs increase and specific energy decreases
Solution Approach 1:
The anode is prelithiated before battery assembly by contacting it with lithium metal or lithium-containing compounds, allowing the anode to be preloaded with lithium ions. This preliminary action ensures that lithium is available for SEI formation during the first charge cycle, eliminating the need to overdimension the cathode and thereby preserving specific energy while maintaining nominal capacity.
Solution Approach 2:
The invention changes the lithium content parameter of the anode from its conventional state to a prelithiated state with excess lithium. This parameter change transforms the anode into a lithium source that can supply lithium during formation, resolving the capacity loss issue without requiring additional cathode material and thus maintaining high specific energy.
2Reliability
If the cathode active material is overdimensioned to compensate for formation loss, then the desired nominal capacity is achieved, but the demand for expensive and toxic metals increases
Solution Approach 1:
The anode is prelithiated before battery assembly by contacting it with lithium metal or lithium-containing compounds, allowing the anode to be preloaded with lithium ions. This preliminary action ensures that lithium is available for SEI formation during the first charge cycle, eliminating the need to overdimension the cathode and thereby reducing demand for expensive and toxic metals like cobalt and nickel.
3Ease of operation
If a complex formation process is implemented to prepare the battery for use, then the battery is ready for deployment, but the production complexity and costs increase
Solution Approach 1:
The anode is prelithiated before battery assembly, and the battery is discharged to a state of charge between -10% and 20% before leaving the production line. This preliminary action during manufacturing eliminates or significantly simplifies the post-production formation process, reducing production complexity and costs while ensuring the battery is ready for immediate deployment.
Solution Approach 2:
The prelithiated anode automatically provides lithium during the first charge cycle to form the SEI layer, eliminating the need for external intervention or complex formation equipment. The battery essentially forms itself during normal charging operations, simplifying the production process while ensuring readiness for use.
4Loss of energy
If the anode is prelithiated, then the battery is ready for use immediately with high specific energy, but additional production steps are required
Solution Approach 1:
The anode is prelithiated before battery assembly by contacting it with lithium metal or lithium-containing compounds. This preliminary action, performed during normal manufacturing processes, enables the battery to achieve high specific energy by eliminating cathode overdimensioning, while the simplicity of the prelithiation method keeps production process complexity manageable.
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 approach reduces the quantity of expensive metals needed, lowers production costs, and eliminates the need for a complex formation process, enabling the battery to be immediately deployed with high specific energy and current-carrying capacity.
Implementation Method 1
the anode active material is prelithiated... Before the first discharging and/or charging of the lithium ion battery, the anode active material is prelithiated
Implementation Method 2
both the cathode active material and the anode active material must be capable of reversibly receiving and releasing lithium ions
Implementation Method 3
The formation of the SEI, which is also regarded as a protective layer, is attributed substantially to decomposition reactions of the electrolyte (dissolved conductive lithium salt in organic solvents) with the surface of the anode active material
Data Source
AI summary
A lithium ion battery includes a cathode having a composite cathode active material, and an anode having an anode active material, where the composite cathode active material has at least a first and a second cathode active material. The first and the second cathode active materials each are selected from the group consisting of layered oxides, compounds having an olivine structure, compounds having a spinel structure, and combinations thereof. The first cathode active material has a degree of lithiation a and the second cathode active material has a degree of lithiation b, where a<1, b<1, and |a−b|<0.1 before a first discharging process and/or charging process of the lithium ion battery. The anode active material is pre-lithiated before the first discharging process and/or charging process of the lithium ion battery. A method for manufacturing is also described.