Functionalized Disordered Carbon Cathode for High Energy Power Lithium Battery
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Solution Overview
Problem
Conventional lithium-ion batteries have low power density due to slow lithium ion diffusion, requiring long recharge times, while supercapacitors have low energy density, limiting their industrial applications. Existing organic and carbon nanotube-based solutions face challenges such as poor electronic conductivity, high costs, and difficulties in mass production.
Innovation Solution
A lithium super-battery featuring a chemically functionalized disordered carbon cathode with functional groups that rapidly and reversibly react with lithium ions, eliminating the need for solid-state diffusion, combined with a lithiated anode material, enabling high energy and power density with stable cycle life and wide temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional lithium-ion batteries use solid-state diffusion for lithium ion transport, then energy density is improved, but power density deteriorates due to slow diffusion rates
Solution Approach 1:
The patent changes the fundamental mechanism of lithium ion transport from solid-state diffusion to solution-phase diffusion in liquid electrolyte. This parameter change enables rapid ion transport (high power density) while maintaining high energy density through the use of lithium metal anode and functionalized carbon cathode materials.
Solution Approach 2:
The patent replaces the mechanical solid-state diffusion process with a chemical electrochemical reaction process in liquid electrolyte. The functional groups on carbon surfaces undergo rapid redox reactions with lithium ions in solution, eliminating the slow solid-state diffusion bottleneck while maintaining high energy storage capacity.
2Power
If supercapacitors use electric double layer formation for energy storage, then power density is improved, but energy density deteriorates
Solution Approach 1:
The patent creates a hybrid system combining features of both batteries and supercapacitors. The functionalized carbon cathode with surface functional groups provides battery-like energy storage through chemical reactions, while the liquid electrolyte enables supercapacitor-like rapid ion transport. This composite approach achieves both high energy density and high power density simultaneously.
Solution Approach 2:
The liquid electrolyte acts as an intermediary medium that enables rapid ion transport between electrodes (supercapacitor feature) while the functional groups on carbon surfaces serve as intermediaries for chemical energy storage (battery feature). This dual intermediary system resolves the contradiction between power density and energy density.
3Reliability
If lithium-ion batteries require long recharge times due to slow diffusion, then cycle life is improved, but productivity deteriorates
Solution Approach 1:
The patent changes the ion transport parameter from slow solid-state diffusion to fast solution-phase diffusion in liquid electrolyte. This enables rapid charging (high productivity) while the stable electrochemical reactions and robust electrode materials maintain long cycle life.
4Use of energy by moving object
If organic molecules are used as cathode material to increase energy density, then electronic conductivity deteriorates
Solution Approach 1:
The patent uses composite carbon materials with surface functional groups instead of pure organic molecules. The carbon backbone provides excellent electronic conductivity, while the surface functional groups (carboxyl, hydroxyl, amine) provide high energy storage capacity through lithium ion reactions. This composite structure resolves the contradiction between conductivity and energy density.
Solution Approach 2:
The carbon material serves as an intermediary conductor that enables electron transport, while the surface functional groups mediate the chemical reactions with lithium ions. This separation of functions (conduction vs. energy storage) resolves the contradiction between electronic conductivity and energy density.
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 lithium super-battery achieves unprecedented combined performance with high energy density, high power density, long cycle life, and wide operating temperature range, bridging the gap between batteries and supercapacitors.
Implementation Method 1
the positive electrode comprises a chemically functionalized disordered carbon (f-DC) having a functional group that reversibly reacts with a lithium atom or ion
Implementation Method 2
The disordered carbon material preferably has a porous structure having a pore size in the range of 1 nm and 50 nm
Implementation Method 3
The high volumetric capacitance density of a supercapacitor derives from using porous electrodes to create a large surface area conducive to the formation of diffuse double layer charges
Implementation Method 4
This electric double layer (EDL) is created naturally at the solid-electrolyte interface when voltage is imposed
Implementation Method 5
Lithium ions in the liquid electrolyte only have to migrate to the edges or surfaces of aromatic ring structures or small graphene sheets in a disordered carbon matrix. No solid-state diffusion is required
Data Source
AI summary
An electrochemical energy storage device, lithium super-battery, comprising a positive electrode, a negative electrode, a porous separator disposed between the two electrodes, and a lithium-containing electrolyte in physical contact with the two electrodes, wherein the positive electrode comprises a disordered carbon material having a functional group that reversibly reacts with a lithium atom or ion. The disordered carbon material is selected from a soft carbon, hard carbon, polymeric carbon or carbonized resin, meso-phase carbon, coke, carbonized pitch, carbon black, activated carbon, or partially graphitized carbon. In a preferred embodiment, a lithium super-battery having a functionalized disordered carbon cathode and a Li4Ti5O12 anode exhibits a gravimetric energy ˜5-10 times higher than those of conventional supercapacitors and a power density ˜10-30 times higher than those of conventional lithium-ion batteries. This device has the best properties of both the lithium ion battery and the supercapacitor.