Prelithiated Anode Particles with Gradient Lithium Concentration
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Solution Overview
Problem
Lithium-ion batteries face challenges with mechanical degradation of anode active materials leading to shortened cycle life, high irreversible capacity, and safety concerns due to the use of discrete lithium metal phases and complex battery manufacturing processes.
Innovation Solution
Development of prelithiated anode active material particles with a lithium concentration gradient, encapsulated in a protecting shell to maintain air stability and safety, and integrated into a lithium-ion battery design that avoids additional electrodes, enhancing cycle life and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-capacity anode active materials (Si, Sn, Ge) are used to increase lithium storage capacity, then specific capacity is improved, but mechanical degradation occurs during charge-discharge cycles leading to shortened cycle life
Solution Approach 1:
The patent applies this principle by coating the anode active material particles with a flexible carbon-containing film that can accommodate the expansion and contraction of the particles during lithium insertion and extraction, preventing mechanical degradation while maintaining high capacity
Solution Approach 2:
The patent creates composite particles consisting of a core anode active material (Si, Sn, or Ge) combined with a carbon-containing material shell, forming a composite structure that combines the high capacity of the metal core with the mechanical stability and conductivity of the carbon shell
2Quantity of substance
If lithium metal phases are used to compensate for irreversible capacity loss, then capacity retention is improved, but safety concerns and handling difficulties increase
Solution Approach 1:
The patent uses carbon-containing materials as an intermediary substance that can store lithium reversibly without the safety hazards of metallic lithium, serving as a mediator between the need for high capacity and safety requirements
Solution Approach 2:
The patent replaces expensive and hazardous lithium metal with abundant, safe carbon-containing materials that can perform the same function of storing lithium ions without the safety risks associated with metallic lithium
3Reliability
If complex battery manufacturing processes are used to address anode degradation, then cycle life is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent applies preliminary action by pre-coating the anode active material particles with protective carbon-containing films before battery assembly, preventing mechanical degradation from occurring in the first place rather than requiring complex post-assembly interventions
Solution Approach 2:
The carbon-containing coating on the anode particles provides self-protection against mechanical degradation during charge-discharge cycles, eliminating the need for additional complex protective structures or manufacturing steps
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 prelithiated anode active material particles with a lithium concentration gradient and protective shell improve cycle life and capacity retention, reducing irreversible capacity loss and simplifying battery manufacturing while maintaining safety and air stability.
Implementation Method 1
The particle is capable of reversibly storing lithium ions therein during the charge or discharge of the battery
Implementation Method 2
improve air stability and safety
Data Source
AI summary
Provided is a prelithiated anode active material particle for use in a lithium-ion battery, the particle is capable of reversibly storing lithium ions therein during a charge or discharge of the battery and comprises an amount of lithium from 1% to 100% of a maximum lithium content that can be contained in the anode active material particle, having a first lithium concentration C1 near a particle surface and a second lithium concentration C2 inside the particle and away from the particle surface and wherein C1<C2.