Surface-Controlled Lithium-Ion Battery for Fast Charging
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Solution Overview
Problem
Conventional lithium-ion batteries suffer from low power density due to slow lithium diffusion processes, requiring long recharge times, while supercapacitors have limited energy storage capacity, necessitating a technology that combines high energy and power density with fast charging capabilities.
Innovation Solution
A surface-controlled, lithium ion-exchanging battery device featuring nano-structured electrodes with high specific surface areas, where lithium ions are stored and exchanged on the surface rather than within the bulk of the electrodes, utilizing functional materials like nano graphene and disordered carbon to facilitate rapid redox reactions and eliminate solid-state diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional lithium-ion batteries use bulk solid electrode materials for lithium storage, then energy density is improved, but power density deteriorates due to slow solid-state diffusion
Solution Approach 1:
The patent employs porous electrode structures with high surface area to volume ratio, allowing lithium ions to access numerous surface sites simultaneously. The porous architecture enables fast ion transport through the electrolyte-filled pores while maintaining high energy density through increased active material surface area, directly resolving the contradiction between energy density and power density.
Solution Approach 2:
The patent fundamentally changes the lithium storage mechanism from bulk solid-state diffusion to surface-controlled ion exchange. By using materials with surface-exposed reactive sites and controlling the electrochemical reactions at the surface rather than in the bulk, the patent achieves both high energy density (through capacity) and high power density (through fast surface kinetics).
2Quantity of substance
If lithium ions diffuse into bulk solid electrode particles during charge/discharge, then energy storage capacity is improved, but recharge time increases
Solution Approach 1:
The patent extracts the rate-limiting solid-state diffusion process from the bulk electrode material and replaces it with surface-controlled ion exchange. By taking out the problematic bulk diffusion step and using only surface reactions with the electrolyte, the patent achieves fast charging while maintaining lithium storage capacity.
Solution Approach 2:
The patent transitions from three-dimensional bulk diffusion to two-dimensional surface reactions. By confining lithium storage to surface sites accessible from the electrolyte dimension, the patent eliminates the slow bulk diffusion pathway while maintaining storage capacity through high surface area materials.
3Power
If supercapacitors use electric double layer formation for energy storage, then power density and charging speed are improved, but energy density deteriorates
Solution Approach 1:
The patent merges the fast surface reaction mechanism of supercapacitors with the high capacity characteristics of lithium-ion batteries. By combining surface-controlled ion exchange (providing fast kinetics) with lithium-containing electrode materials (providing high capacity), the patent achieves both high power density and high energy density in a single system.
Solution Approach 2:
The patent uses composite electrode materials that combine conductive carbon structures with lithium-containing compounds. This composite approach provides both the fast electron transport and surface reaction sites of supercapacitors and the high lithium storage capacity of battery materials, resolving the energy density limitation of pure supercapacitors.
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 energy densities comparable to lithium-ion batteries and power densities exceeding those of supercapacitors, enabling rapid charging and discharging in seconds, with enhanced safety due to uniform lithium deposition and reduced dendrite formation.
Implementation Method 1
The lithium storage mechanism in both the anode and the cathode is surface-controlled, obviating the need for solid-state diffusion of lithium
Implementation Method 2
obviating the need for solid-state diffusion of lithium, which otherwise is very slow
Implementation Method 3
utilizing functional materials like nano graphene and disordered carbon to facilitate rapid redox reactions
Implementation Method 4
enhanced safety due to uniform lithium deposition and reduced dendrite formation
Data Source
AI summary
A surface-controlled, lithium ion-exchanging battery device comprising: (a) A positive electrode (cathode) comprising a first functional material having a first lithium-capturing or lithium-storing surface; (b) A negative electrode (anode) comprising a second functional material having a second lithium-capturing or lithium-storing surface; (c) A porous separator disposed between the two electrodes, and (d) A lithium-containing electrolyte (preferably liquid or gel electrolyte) in physical contact with the two electrodes; wherein at least one of the two electrodes contains therein a lithium source (e.g., lithium foil, lithium powder, stabilized lithium particles, etc) prior to the first charge or the first discharge cycle of the battery device. This new generation of energy storage device exhibits the best properties of both the lithium ion battery and the supercapacitor.