(1、北京有色金屬研究總院, 北京 100088
2、北京科技大學(xué)固體電解質(zhì)冶金測(cè)試技術(shù)國(guó)家專業(yè)實(shí)驗(yàn)室, 北京 100083)
摘 要: 用熱重分析方法并配合中間產(chǎn)物及最終產(chǎn)物的物相鑒定，研究了LiCo1-xNixO2合成過(guò)程的機(jī)理及產(chǎn)物的結(jié)構(gòu)和性能。碳酸鋰和鈷、鎳的堿式碳酸鹽，在共混后熱合成LiCo1-xNixO2的過(guò)程分兩步進(jìn)行，第一步為堿式碳酸鎳(鈷)鹽的熱分解(<300 ℃)，第二步 (>300 ℃)包括碳酸鋰的分解和LiCo1-xNixO2的合成。溫度升高，合成產(chǎn)物中鋰含量增加，晶格參數(shù)增大，生成物為具有單相結(jié)構(gòu)的LiCoO2和LiNiO2固溶體。隨著LiCo1-xNixO2中 x 值的增加，晶格參數(shù)增大。合成過(guò)程中碳酸鹽分解產(chǎn)生的CO對(duì)Co++、Ni++ 氧化成Co+++、Ni+++產(chǎn)生影響，因此合成的氣氛和原料對(duì)產(chǎn)物有明顯的影響。通過(guò)合成條件的優(yōu)化得到的LiCo0.5Ni0.5O2和LiNiO2 放電量均可達(dá)到LiCoO2的水平。
關(guān)鍵字: LiCo1-xNixO2 合成機(jī)理 鋰離子電池
（1.General Research Institute of Nonferrous Metals, Beijing 100088 ;
2.National Laboratory on Solid Electrolytes and Metallurgical Testing Techniques, University of Science and Technology Beijing, Beijing 100083）
Abstract:The mechanism of LiCo1-xNixO2(x=0~1) synthesis from Co and/or Ni carbonates and Lithium carbonate was investigated by thermogravimetric analysis. The products during the process were identified by X-ray diffraction. The results indicated that the process includes two steps. The first step is decomposition of Co and/or Ni carbonates(below 300 ℃), followed by Lithium carbonate decomposing and LiCo1-xNixO2 forming (300～900 ℃). LiCo1-xNixO2 is characterized by single phase and solid solution of LiCoO2 and LiNiO2. The cell volumes of LiCo1-xNixO2 crystals increase with x. Starting materials affect Ni+++ and/or Co+++ forming because of the CO reduction atmosphere produced during the carbonates decomposing. LiCo1-xNixO2(x≥0.5) can be synthesized by heating carbonates in air. LiNiO2 was only obtained from LiOH and Ni(OH)2 in oxygen. Through optimization of synthesis conditions were obtained LiCo0.5Ni0.5O2 and LiNiO2, which have better performances for cathode materials of Li-ion batteries than LiCoO2.
Key words: LiLiCo1-xNixO2 synthesis lithium-ion battery
