Sodium-Ion Battery Metal Plating Anode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sodium-ion batteries face limitations in capacity and energy density due to the use of transition metal hexacyanoferrate electrodes, which require operation below 1.23 V and can only insert/extract one sodium-ion per formula unit, and existing anode materials face challenges such as slow sodiation kinetics and dissolution.
Innovation Solution
A novel structure for rechargeable sodium-ion batteries using a Prussian-blue analogue (PBA) cathode where sodium-ions directly electroplate onto an anode current collector or structural substrates without chemical interaction, employing high sodium concentrated Fe-hexacyanoferrate and Mn-hexacyanoferrate cathodes, and utilizing a non-aqueous electrolyte to enhance capacity and energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If transition metal hexacyanoferrate electrodes are used, then the battery can operate with a simple structure, but the capacity and energy density are limited due to operation below 1.23 V and only one sodium-ion insertion/extraction per formula unit
Solution Approach 1:
The patent changes the operating voltage parameter from below 1.23 V to higher voltages by using a metal plating anode system. This allows the cathode to operate at higher potentials while the anode potential is determined by the metal plating/dissolution reaction, thereby increasing the cell voltage and energy density without changing the cathode material structure.
Solution Approach 2:
Instead of using conventional insertion/extraction mechanisms where sodium ions are stored in the anode material lattice, the patent inverts the approach by using metal plating (deposition) on the anode surface during charging and dissolution during discharge. This eliminates the constraint of anode material capacity and allows unlimited sodium-ion storage based on plating thickness.
2Reliability
If conventional anode materials are used, then the battery structure is complete, but slow sodiation kinetics and dissolution issues reduce cycling life and performance
Solution Approach 1:
The patent extracts the slow sodiation kinetics problem by removing conventional anode materials (graphite, hard carbon) that require diffusion-based sodium insertion. Instead, it uses metal plating which occurs through direct electrochemical deposition on the anode surface, eliminating the diffusion barrier and achieving fast sodium-ion kinetics.
Solution Approach 2:
The patent replaces the mechanical diffusion-based sodiation process in conventional anodes with an electrochemical plating process. The sodium ions are deposited directly onto the anode surface through electron transfer reactions, which is a surface phenomenon rather than a bulk diffusion process, thereby achieving much faster kinetics.
3Quantity of substance
If active anode materials are used, then the battery can achieve higher capacity, but the complexity of the system increases and energy density is reduced
Solution Approach 1:
The patent applies the self-service principle by using the cathode material itself (high sodium concentrated Fe-hexacyanoferrate or Mn-hexacyanoferrate) as the source of sodium ions that plate onto the anode. The anode serves dual purposes: as the collection surface for plated metal and as part of the electrochemical system, eliminating the need for separate active anode materials and simplifying the overall battery structure.
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
This approach allows for improved cycling life and energy density by eliminating the need for active anode materials, enabling sodium-ion batteries to operate at higher voltages and maintain a solid electrolyte interphase layer for efficient ion transfer, thereby increasing the battery's capacity and reducing energy consumption.
Implementation Method 1
sodium-ions directly electroplate onto an anode current collector or structural substrates
Implementation Method 2
maintain a solid electrolyte interphase layer for efficient ion transfer
Data Source
AI summary
A method is provided for cycling power in a transition metal cyanometallate (TMCM) cathode battery. The method provides a battery with a TMCM cathode, an anode, and an electrolyte, where TMCM corresponds to the chemical formula of AXM1NM2M(CN)Y-d(H2O), where “A” is an alkali or alkaline earth metal, and where M1 and M2 are transition metals. The method charges the battery using a first charging current, or greater. In response to the charging current, a plating of “A” metal is formed overlying a plating surface of the anode. In response to discharging the battery, the “A” metal plating is removed from the anode plating surface. In one aspect, in an initial charging of the battery, a permanent solid electrolyte interphase (SEI) layer is formed overlying the anode plating surface. In subsequent charging and discharging cycles, the permanent SEI layer is maintained overlying the anode plating surface.