Lithium Metal Anode Battery Design for High Energy Density
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Solution Overview
Problem
Conventional lithium-ion batteries face limitations in energy density and power density due to the use of intercalation anodes, which contribute to 'deadweight' and require matching storage capacities between cathode and anode, restricting their performance, while lithium metal batteries suffer from safety issues and poor power density.
Innovation Solution
A high energy density, high power lithium metal anode rechargeable battery design featuring an ultra-thin lithium metal anode, a high energy density cathode with a non-ion conducting separator, and a hybrid electrolyte system that allows for >1 C discharge at room temperature, achieving volumetric energy density of >1000 Wh/L and gravimetric energy density of >350 Wh/kg with extended cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If intercalation anodes are used in lithium-ion batteries, then safety and cycle life are improved, but energy density and power density are limited due to deadweight and capacity matching requirements
Solution Approach 1:
The patent removes the conventional intercalation anode structure entirely and replaces it with a lithium metal anode. This extraction of the limiting factor (intercalation anode deadweight and capacity matching constraint) enables the use of high-capacity cathodes without being constrained by anode capacity, thereby achieving high energy density while maintaining safety through advanced electrolyte and separator designs
Solution Approach 2:
The patent changes the anode material parameter from intercalation materials (graphite, silicon) to lithium metal, fundamentally altering the electrochemical properties. This parameter change enables higher operating voltages and energy densities while the accompanying electrolyte and separator modifications ensure safety and cycle life are maintained
2Use of energy by moving object
If lithium metal anode is used, then energy density is improved, but safety issues and poor power density occur due to mossy lithium and dendrite growth
Solution Approach 1:
The patent introduces a carefully engineered electrolyte system (comprising specific carbonate esters and chain ethers) and separator design as intermediaries between the lithium metal anode and cathode. These intermediaries control lithium ion transport, prevent dendrite formation, and ensure safe operation, enabling the use of high-energy-density lithium metal anodes without compromising safety
Solution Approach 2:
The patent employs a composite electrolyte system combining multiple components (cyclic carbonate esters and chain ethers) with specific ratios to achieve both high ionic conductivity for power density and dendrite suppression for safety. The hybrid electrolyte composition creates a protective interface on the lithium anode that prevents mossy lithium formation while maintaining high energy density
3Reliability
If conventional solid polymer electrolyte is used, then safety is improved, but power density and room temperature performance are limited due to thick electrolyte and low conductivity
Solution Approach 1:
The patent changes the electrolyte state parameter from solid polymer to liquid hybrid system, fundamentally improving ionic conductivity and power density. The liquid electrolyte components enable fast ion transport at room temperature while the overall cell design (thin electrolyte layer, high-capacity electrodes) maintains safety, achieving both high power density and safe 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 energy and power densities with improved cycle life, retaining over 80% capacity after 100 cycles, and demonstrates enhanced safety and operational stability at room temperature, surpassing the limitations of conventional lithium-ion and lithium metal batteries.
Implementation Method 1
a non-aqueous electrolyte selected to have electrochemical stability at the potential of the high voltage cathode material versus lithium
Implementation Method 2
high energy density, high power lithium metal anode rechargeable battery design featuring an ultra-thin lithium metal anode, a high energy density cathode
Data Source
AI summary
A high energy density, high power lithium metal anode rechargeable battery having volumetric energy density of >1000 Wh/L and/or a gravimetric energy density of >350 Wh/kg, that is capable of >1 C discharge at room temperature. In some embodiments, a high power lithium metal anode rechargeable battery of the present disclosure includes a lithium metal anode having a thickness of less than 20 μm and a ratio of anode capacity (n) to cathode capacity (p) in a discharged state, i.e., n/p, in a range of 0.8 to less than or equal to 1 or in a range of 0.9 to less than or equal to 1. In some embodiments, a high power lithium metal anode rechargeable battery of the present disclosure further includes a high-voltage cathode and a hybrid separator.