Lithium Iron Phosphate Battery Particle Mix for Power and Cycle Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium iron phosphate batteries face challenges in simultaneously achieving high power and long cycle life due to issues with conductivity, lithium-ion diffusion, and poor cycle life during high-rate charging and discharging.
Innovation Solution
A lithium iron phosphate battery design incorporating both large-particle and small-particle cathode and anode active materials, which addresses poor rate performance and polarization issues when using only large particles, and excessive side reactions when using only small particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only large-particle cathode and anode active materials are used, then polarization is reduced, but rate performance deteriorates
Solution Approach 1:
The cathode and anode active materials are segmented into multiple particle sizes (large particles and small particles). Large particles reduce polarization while small particles improve rate performance. The battery uses a combination of both particle sizes to achieve both low polarization and high rate performance simultaneously.
2Productivity
If only small-particle cathode and anode active materials are used, then rate performance is improved, but excessive side reactions occur leading to poor cycle performance
Solution Approach 1:
The active materials are segmented into different particle sizes with specific functions: small particles provide high rate performance while large particles reduce side reactions and improve cycle stability. The combination resolves the trade-off between rate performance and cycle life.
3Power
If lithium iron phosphate cathode material is used for high-rate charging and discharging, then power requirements are met, but conductivity is poor and lithium-ion diffusion is slow
Solution Approach 1:
The cathode material is segmented into different particle sizes. Smaller particles provide shorter lithium-ion diffusion paths improving conductivity and rate performance, while larger particles maintain structural stability. The combination enables high-rate charging and discharging with improved conductivity.
4Power
If lithium iron phosphate battery is designed for high power, then power requirements are met, but cycle life deteriorates
Solution Approach 1:
The battery uses segmented particle sizes in both cathode and anode. Small particles enable high power through fast lithium-ion diffusion, while large particles provide structural stability and reduce side reactions during cycling, thereby extending cycle life.
Solution Approach 2:
The battery employs a composite structure combining large and small particles of cathode and anode active materials. This composite approach integrates the advantages of both particle sizes: high power from small particles and long cycle life from large particles.
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 combined use of large and small particles in cathode and anode active materials improves rate performance and ensures excellent cycle performance and high energy efficiency.
Implementation Method 1
lithium-ion diffusion
Implementation Method 2
lithium iron phosphate battery
Data Source
AI summary
The present disclosure provides a lithium iron phosphate battery and a hybrid vehicle. The lithium iron phosphate battery includes a first cathode active material, a second cathode active material, a first anode active material, and a second anode active material. A median particle size of the first cathode active material is different from a median particle size of the second cathode active material. A median particle size of the first anode active material is different from a median particle size of the second anode active material.