Development of Continuous Synthesis Method of Lithium Transition Metal Oxide Fine Particles via Reactive Crystallization in Supercritical Water

超临界水中反应结晶连续合成锂过渡金属氧化物细粒方法的进展

• 批准号: 10555261
• 负责人: ARAI Kunio
• 金额: $ 7.74万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10555261/
• 关键词: Lithium ion second battery; Cathode material; LiCoO2; LiMn2O4; Fine crystal; Hydrothermal synthesis; Supercritical water; Charge-discharge property; LiCo0_2; LiMn_20_4; 超臨界水; 反応晶析; 硝酸コバルト; 水酸化リチウム

In this study, we use supercritical hydrothermal synthesis method to continuously produce LiCoOィイD22ィエD2 fine crystals that are used as for the cathode materials of rechargeable lithium ion batteries. LiOH and Co(NOィイD23ィエD2)ィイD22ィエD2 were chosen as starting materials. For oxidizing Co(II) to Co(III), O2 was introduced into the reactor after decomposing aqueous HィイD22ィエD2OィイD22ィエD2 solution in a preheating tubing. LiCoOィイD22ィエD2 particles formed in a single phase at supercritical conditions (400℃ and 30 MPa). On the other hand, CoィイD23ィエD2OィイD24ィエD2 phase formed from the same starting solutions under subcritical conditions (300℃, 350℃ and 30 MPa). This results from an enhancement of oxidation of CoィイD12+ィエD1 due to homogeneous supercritical conditions. Scanning electron micrographs showed that the particle size was in the range of 600 to 1,000 nm in diameter. Using the same method, we could produce another cathode material, LiMnィイD22ィエD2OィイD24ィエD2. Particles obtained were hexagonal plate like particle with 100 - 200 nm in diameter. Electrochemical characterization was performed by a constant current discharge and charge test. The electrochemical capacity of particle obtained was as low as 120 mAh/g, but a loss of capacity was below 5 % during 50 charge-discharge cycles. Little decrease in the discharge capacity suggests high stability of the LiCoOィイD22ィエD2 and LiMnィイD22ィエD2OィイD24ィエD2 crystals prepared by this method.

在本研究中，我们采用超临界水热合成方法连续生产LiCoOィイD22ィエD2细晶，用作可充电锂离子电池的正极材料。选择LiOH和Co(NOィイD23ィエD2)ィイD22ィエD2作为起始材料。为了将Co(II)氧化成Co(III)，在预热管中分解HiiD22iiD2OiiD22iiD2水溶液后将O2引入反应器中。 LiCoOィイD22ィエD2 颗粒在超临界条件（400℃和30 MPa）下形成单相。另一方面，在亚临界条件（300℃、350℃和30 MPa）下，由相同的起始溶液形成CoィイD23ィエD2OィイD24ィエD2相。这是由于均匀超临界条件导致 CoiiD12+iiD1 氧化增强的结果。扫描电子显微照片显示颗粒尺寸直径在600至1,000 nm范围内。采用同样的方法，我们可以生产另一种正极材料LiMnィイD22ィエD2OィイD24エD2。获得的颗粒是直径100-200nm的六角板状颗粒。通过恒流放电和充电测试进行电化学表征。所得颗粒的电化学容量低至120mAh/g，但在50次充放电循环期间容量损失低于5%。放电容量几乎没有下降表明通过该方法制备的LiCoOiiD22ィエD2和LiMnィイD22ィエD2OィイD24エD2晶体具有高稳定性。

项目成果

Kanamura et al.: "Preparation and Electrochemical Characterization of LiCo02 Single Crystal Particles Prepared by Supercritical Water Synthesis(SCWS)"Proceeding of MRS Spring 1999 Meeting. in press. (2000)

Kanamura等人：“通过超临界水合成(SCWS)制备的LiCoO 2 单晶颗粒的制备和电化学表征”MRS 1999年春季会议记录。

Adschiri et al.: "Continuous Production of LiCoO2 fine crystals for lithium batteries by hydrothermal synthesis under supercritical condition"High pressure research. (in press). (2000)

Adschiri等人：“超临界条件下水热合成连续生产锂电池用LiCoO2细晶”高压研究。

K. Kanamura, A. Goto, T. Umegaki, K. Toyoshima, K.-I. Okada, Y. Hakuta, M. Adschiri and K. Arai: "Preparation of LiCoO2 Cathode Material for Rechargeable Lithium Batteries Using Super Critical Water Synthesis"Proceedings of 196th Meeting of The Electroche

K. Kanamura、A. Goto、T. Umegaki、K. Toyoshima、K.-I。

Adschiri et al.: "Continuous Production of LiCo02 fine crystals for lithium batteries by hvdrothermal synthesis under supercrical condition"High pressure research. in press. (2000)

Adschiri等人：“超临界条件下通过水热合成连续生产锂电池用LiCo02细晶”高压研究。

Kanamura et al.: "Preparation of LiCoO2 Cathode Material for Rechargeable Lithium Batteries Using Super Critical Water Synthesis"Proceeding of 1999 Joint International Meeting. 186-186 (1999)

Kanamura 等人：“利用超临界水合成法制备可充电锂电池用 LiCoO2 正极材料”1999 年联合国际会议论文集。