Semi-solid Li/O2 Battery Catholyte Flow Network
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Solution Overview
Problem
Lithium oxygen batteries face challenges with low discharge capacities, space inefficiency, and high costs due to passivation of current collectors by lithium oxide species, which limits their application in electric vehicles and renewable energy plants.
Innovation Solution
A lithium oxygen battery with a semi-solid catholyte comprising a non-aqueous electrolyte, dissolved oxygen, and conductive carbon black particles, which are insoluble and form a percolating network for efficient electron transfer and oxygen redox reactions, preventing passivation and enhancing discharge capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a solid cathode is used in Li/O2 batteries, then the battery structure is simple, but the discharge capacity is limited due to passivation by lithium oxide species
Solution Approach 1:
The patent transforms the static solid cathode into a dynamic flowable catholyte system. The catholyte containing carbonaceous particles is continuously circulated through the cathode compartment, enabling dynamic renewal of reactive surfaces and preventing passivation by lithium oxide species, thereby significantly improving discharge capacity while maintaining reasonable structural complexity
Solution Approach 2:
The patent applies hydraulic principles by using a flowable liquid medium (catholyte) instead of a solid cathode. The catholyte is pumped through the cathode compartment, utilizing fluid dynamics to continuously supply fresh reactive material and remove passivation products, thus resolving the contradiction between structural simplicity and discharge capacity
2Reliability
If conventional Li/O2 battery configuration is used, then the battery can operate, but it occupies large space and has high cost
Solution Approach 1:
The patent extracts the active cathode material from a fixed solid structure and places it in a flowable liquid medium. This allows the active material to be concentrated in a smaller volume while maintaining operational reliability, as the flowable catholyte can be efficiently circulated and utilized within a compact battery design
Solution Approach 2:
The patent changes the physical state parameter of the cathode from solid to flowable liquid suspension. This parameter change enables higher concentration of active material per unit volume and more efficient utilization, reducing the overall battery volume required to achieve the same operational reliability
3Productivity
If solid lithium peroxide forms on cathode surface, then the battery can discharge, but the conductivity decreases causing high recharge overpotentials
Solution Approach 1:
The patent extracts the discharge products (lithium peroxide and lithium oxide) from adhering to the solid cathode surface by dissolving them in the flowable catholyte. The soluble discharge products are carried away by the circulating catholyte, preventing electrode insulation and maintaining high conductivity for efficient recharge
Solution Approach 2:
The patent introduces the flowable catholyte as an intermediary medium between the cathode and discharge products. This intermediary continuously removes lithium peroxide and lithium oxide from the cathode surface through dissolution and transport, preventing passivation and maintaining electrical conductivity for reliable recharge operation
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 battery achieves high discharge capacities (>500 mAh/g) and power densities (>20 mW/cm²) with reduced inactive material volume and weight, making it cost-effective and suitable for electric vehicles and renewable energy storage.
Implementation Method 1
conductive carbon black particles, which are insoluble and form a percolating network for efficient electron transfer
Implementation Method 2
The oxygen redox reaction (ORR) takes place at the solid cathode/electrolyte interface
Implementation Method 3
dissolved oxygen
Data Source
AI summary
The present disclosure relates to a lithium oxygen battery with a non-aqueous flowable semi-solid catholyte comprising an electrolyte, dissolved oxygen and carbonaceous particles which are not soluble in the catholyte. The battery also comprises a lithium anode, electrical contacts, an oxygen inlet, a porous cathode current collector and a pump. The oxygen-enriched catholyte is pumped through the cell of the battery and the oxygen redox reaction may take place on the carbonaceous particles which form a conducting percolating network. Also disclosed is a semi-solid, non-aqueous catholyte comprising an electrolyte, dissolved oxygen and carbonaceous particles; the use of the lithium oxygen battery; and the use in electric vehicle and for stationary applications.