Lithium Composite Oxide Cathode Surface Treatment for Battery Efficiency
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Solution Overview
Problem
Conventional lithium ion secondary batteries face challenges in achieving high initial efficiency and cycle retention, which are essential for improved performance in portable electronics and vehicles.
Innovation Solution
A process involving steps of washing a lithium-containing composite oxide with an acidic solution, followed by contact with specific aqueous solutions containing anions and cations, and subsequent heating to form a cathode active material, enhancing both initial efficiency and cycle retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If no surface treatment is applied to lithium-containing composite oxide, then manufacturing process is simple, but both initial efficiency and cycle retention are insufficient
Solution Approach 1:
The invention introduces aqueous ammonia solution as an intermediary substance that mediates between the lithium-containing composite oxide and the final battery performance. The ammonia solution acts as a treatment medium that forms a protective surface layer, improving both initial efficiency and cycle retention. This intermediary treatment step is simple to implement (dipping or coating followed by drying and heating) but provides significant performance enhancement.
Solution Approach 2:
The invention applies preliminary surface treatment to the lithium-containing composite oxide before it is assembled into the battery. By pre-forming the protective ammonia-treated layer on the material surface, the battery is prepared in advance to achieve both high initial efficiency and good cycle retention from the first charge-discharge cycle, eliminating the need for complex post-assembly treatments.
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 process significantly improves the initial efficiency and cycle retention of lithium ion secondary batteries, leading to better performance and durability.
Implementation Method 1
treating a powder of a lithium-containing composite oxide containing Li element and a transition metal element with nitric acid, treating it with an ammonia gas
Implementation Method 2
subjecting it to a heat treatment
Data Source
AI summary
To provide a process for producing a cathode active material for a lithium ion secondary battery which can improve the initial charge and discharge efficiency (initial efficiency) and the cycle retention of a lithium ion secondary battery.A process for producing a cathode active material for a lithium ion secondary battery, which comprises a step (I) of bringing a lithium-containing composite oxide (I) containing Li element and a transition metal element into contact with a washing liquid and then separating it from the washing liquid to obtain a lithium-containing composite oxide (II), a step (II) of bringing the lithium-containing composite oxide (II) into contact with a composition (1) consisting of an aqueous solution containing an anion (A) preferably containing F and a composition (2) consisting of an aqueous solution containing a cation (M) preferably containing Al or Zr, and a step (III) of heating the lithium-containing composite oxide (II) after the step (II), in this order.