| 环境稳定型补锂剂的制备及其电化学性能 | |
| Preparation and electrochemical properties of high-stability cathode prelithiation additive | |
| 摘要: 基于不同单金属氧化物对草酸锂(Li2C2O4，LCO)分解的促进效果，以CuO-Mn2O3混合物为前驱体，采用简便的固相烧结法合成了一系列 Mn、Cu 物质的量之比(x)不同的 CuMnxO1+1.5x双金属氧化物催化剂。通过 X 射线衍射(XRD)、X 射线光电子能谱(XPS)、N2吸附-脱附等温线和扫描电子显微镜(SEM)等方法表征了材料的结构组成与微观形貌，并探究了其对LCO电化学活性的影响规律。结果表明，在0.05C和2.5~4.5 V下，以CuMn1.1O2.7为催化剂时LCO的充电比容量可达404.7 mAh·g-1，同时脱锂电位降低至 4.44 V，首次库仑效率仅为 1.3%，可作为正极补锂添加剂应用于磷酸铁锂(LFP)体系；此外，采用密度泛函理论(DFT)计算揭示了 LCO分解的速率控制步骤和催化剂的作用机制。将一定量的 LCO/CuMn1.1O2.7补锂剂添加至 LFP浆料中制作成扣式半电池，并对其进行电化学性能测试，结果表明，在最佳补锂剂含量下，相应 LFP电极的首次充电比容量为 205.9 mAh·g-1，LCO的实际利用率可达74.1%，而且补锂剂的添加能改善LFP的循环性能。 | |
| 关键词: 磷酸铁锂|正极补锂添加剂|草酸锂|金属氧化物 | |
| 基金项目: 中央引导地方科技发展资金储备项目(No.2024ZY02005)资助。 | |
| Abstract: In this work, based on the catalytic effect of several metal oxides on the decomposition of lithium oxalate (Li2C2O4, LCO), a series of CuMnxO1+1.5x bimetallic oxides with different molar ratios (x) of Mn and Cu were synthesized via the controlled calcination of CuO-Mn2O3 mixture. The structural composition and surface morphology were characterized using the X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption isotherms, and scanning electron microscopy (SEM). The catalysts were applied in the electrochemical test of LCO at 0.05C within the voltage range of 2.5-4.5 V. Results showed that the charge specific capacity of LCO could be increased to 404.7 mAh·g-1 and delithium potential can be reduced to 4.44 V with the initial Coulombic efficiency of 1.3% over CuMn1.1O2.7 catalyst, which could match with the lithium iron phosphate (LFP) materials as a cathode prelithiation additive. The rate determining step of LCO decomposition and the mechanism of the catalyst were revealed by density functional theory (DFT) calculations. Subsequently, a certain amount of LCO/CuMn1.1O2.7 was added to the LFP slurry, and the corresponding electrochemical performance was tested by assembling half-cells. It was found that under the optimal lithium supplement content, the initial charge capacity of the LFP electrode was 205.9 mAh·g-1, and the practical capacity utilization of LCO could reach 74.1%. Moreover, the cycle performance of LFP can also be improved by using an LCO prelithiation additive. | |
| Keywords: lithium iron phosphate|cathode prelithiation additive|lithium oxalate|metal oxide | |
| 投稿时间：2024-12-11 修订日期：2025-04-15 | |
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