Mixed Cathode Material for Dual-Ion Battery Voltage Stability
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Solution Overview
Problem
Lithium-ion batteries face limitations in extending discharge and charge voltage cutoff limits, which affects their life and energy performance, necessitating improved energy designs that enhance these aspects.
Innovation Solution
A mixed positive electrode material is developed, comprising a primary material with nickel (30-99 weight percent) for lithium ion intercalation and a secondary material for sodium ion intercalation, integrated with a current collector and electrochemically active layer in a rechargeable battery, along with a negative electrode and electrolyte, to facilitate efficient ion transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium-ion batteries operate outside their designed voltage boundaries, then energy performance and life are improved, but cell stability and reliability deteriorate
Solution Approach 1:
The positive electrode material is designed to perform multiple functions: it can intercalate both lithium ions (primary function) and sodium ions (secondary function). This multi-functionality allows the battery to operate flexibly across different voltage ranges and chemical environments, improving energy performance while maintaining stability through reversible dual-ion interactions.
Solution Approach 2:
The patent employs a composite positive electrode material structure that combines lithium-intercalating phases with sodium-intercalating phases. This composite approach enables the material to accommodate a broader range of operating conditions, extending voltage cutoff limits while preserving cell reliability through the synergistic behavior of different ion-host structures.
2Duration of action of moving object
If the voltage cutoff limits are extended, then life and energy performance are improved, but the complexity of the battery system increases
Solution Approach 1:
The patent merges the functions of separate lithium-based and sodium-based positive electrode materials into a single composite material system. This combination eliminates the need for separate battery cells or complex switching mechanisms, extending battery life through dual-ion reversibility while avoiding additional system complexity.
3Quantity of substance
If nickel content in primary positive electrode material is increased, then energy density is improved, but structural stability at extreme voltages deteriorates
Solution Approach 1:
The composite positive electrode material combines high-nickel lithium-intercalating phases (providing high energy density) with sodium-intercalating phases (providing structural stability). The sodium-host structures act as stable frameworks that can reversibly accommodate sodium ions at extreme voltages, preventing degradation of the high-nickel components while maintaining high energy capacity.
Solution Approach 2:
The patent utilizes parameter changes in the electrochemical environment (voltage, ion type) to switch between lithium and sodium intercalation modes. By changing the operating parameters, the material exhibits different structural behaviors that optimize both energy density and stability under different conditions.
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 solution extends the life and energy performance of lithium-ion batteries by allowing reversible intercalation of both lithium and sodium ions, thereby optimizing battery operation within broader voltage and temperature ranges.
Implementation Method 1
The primary positive electrode material has a structure that allowed intercalation and de-intercalation of lithium ions
Implementation Method 2
The secondary positive electrode material has a structure that allows intercalation and deintercalation of sodium ions
Implementation Method 3
an electrochemically active layer disposed over the current collector
Data Source
AI summary
A mixed positive electrode material for a battery includes a primary positive electrode material that includes nickel in an amount from about 30 weight percent to about 99 weight percent of the total weight of the primary positive electrode material. The primary positive electrode material has a structure that allowed intercalation and de-intercalation of lithium ions. The mixed positive electrode material also includes a secondary positive electrode material having a structure that allows intercalation and de-intercalation of sodium ions. Advantageously, the mixed positive electrode material can be used as the cathode active material in a battery.