TMCCC Cell Electrolyte With Dinitrile Additive for Longer Cycle Life

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Solution Overview

Problem

Existing electrochemical cells with transition metal cyanide coordination compound (TMCCC) electrodes face degradation issues due to parasitic reactions and water impurities, leading to reduced energy utilization and shortened device lifetime.

Innovation Solution

Incorporating a dinitrile additive into the liquid electrolyte, which includes a mononitrile solvent and alkali metal salts, to form a chemically stable chelation complex with dissolved transition metal ions and suppress unwanted reactions with water, thereby enhancing cell stability and lifetime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a liquid electrolyte is used in TMCCC electrochemical cells, then ion intercalation and energy storage are achieved, but parasitic reactions occur leading to cell degradation

Engineering Contradiction:

Improveenergy storageVSAvoidcell degradation

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

A dinitrile additive is introduced as an intermediary substance in the electrolyte that preferentially reacts with transition metal ions to form stable chelation complexes. This intermediary action prevents the transition metal ions from participating in parasitic reactions with other electrolyte components, thereby reducing cell degradation while maintaining energy storage functionality

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical composition of the electrolyte is modified by adding dinitrile compounds with specific molecular structures and concentrations. This parameter change alters the reaction dynamics in the system, creating more stable transition metal ion complexes that resist parasitic reactions and improve overall cell reliability

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the voltage window is narrowed to reduce parasitic reactions, then cell degradation is diminished, but energy utilization is significantly reduced

Engineering Contradiction:

Improvecell degradationVSAvoidenergy utilization

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The dinitrile additive acts as a mediator that allows the cell to operate at higher voltages by stabilizing transition metal ions. This intermediary protection enables broader voltage window utilization without the usual penalty of increased parasitic reactions, thus improving energy utilization while maintaining reliability

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If different liquid electrolytes are substituted to reduce parasitic reactions, then reaction rates are reduced, but electrolyte conductivity decreases lowering maximum power

Engineering Contradiction:

Improveparasitic reaction rateVSAvoidmaximum charge and discharge power

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The electrolyte is formulated as a composite system combining acetonitrile solvent, alkali metal salts, and dinitrile additives. This composite composition leverages the high conductivity of acetonitrile while the dinitrile components provide chemical stability and low parasitic reactions, achieving both high power and high reliability simultaneously

Inventive Principle:

Principle #40Composite materials

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 dinitrile additive significantly reduces parasitic reactions and improves cell lifetime by preventing the formation of manganese oxide precipitates and enhancing tolerance to water impurities, allowing for fast discharge to high depth of discharge.

Implementation Method 1

the dinitrile additive significantly reduces parasitic reactions and improves cell lifetime by preventing the formation of manganese oxide precipitates

Methodology Applied

Scientific EffectChelation:

Implementation Method 2

energy storage is achieved by ion intercalation in one or more electrodes including the TMCCC material

Methodology Applied

Scientific EffectIntercalation:

Data Source

PatentUS20250349895A1Electrochemical cell with tmccc electrodes in an acetonitrile solvent including a dinitrile additive

Publication Date: 2025.11.13 NATRON ENERGY INC

AI summary

A system and method for a liquid electrolyte used in secondary electrochemical cells having at least one electrode including a TMCCC material, the liquid electrolyte enabling an increased lifetime while allowing for fast discharge to extremely high depth of discharge. The addition of dinitriles to liquid electrolytes in electrochemical cells in which energy storage is achieved by ion intercalation in transition metal cyanide coordination compounds (TMCCC) has the advantage of increasing device lifetime by inhibiting common chemical and electrochemical degradation mechanisms.