CAJ | 학술논문

用响应面法优化了低温碳热还原合成LiFePO4/C的工艺,用中心组合设计研究了蔗糖用量、焙烧温度、焙烧时间和低温反应温度四因素对放电比容量的影响.结果表明,放电比容量与四因素关系符合二次模型,焙烧温度和蔗糖量以及两者的交互作用对放电比容量影响较为显著,各个因素的二次方影响高度显著.由模型得出的最优操作条件为:焙烧温度718℃;焙烧时间10.88 h;蔗糖量0.866 g?g?1 LiFePO4;热处理温度105℃.该条件下LiFePO4/C的实际放电比容量为140.6 mA?h?g?1,与模型预测值142.03 mA?h?g?1无显著差异.
용향응면법우화료저온탄열환원합성LiFePO4/C적공예,용중심조합설계연구료자당용량、배소온도、배소시간화저온반응온도사인소대방전비용량적영향.결과표명,방전비용량여사인소관계부합이차모형,배소온도화자당량이급량자적교호작용대방전비용량영향교위현저,각개인소적이차방영향고도현저.유모형득출적최우조작조건위:배소온도718℃;배소시간10.88 h;자당량0.866 g?g?1 LiFePO4;열처리온도105℃.해조건하LiFePO4/C적실제방전비용량위140.6 mA?h?g?1,여모형예측치142.03 mA?h?g?1무현저차이.
A low-temperature carbothermal reduction method was used to prepare the LiFePO4/C composites, and the response surface methodology was used to optimize the preparation process parameters. The sucrose amount, sintering temperature, sintering time and heating temperature were selected as four independent variables. The experimental data were collected by the central composite rotatable design (CCD), and the effects of the above four independent variables on the discharge capacity of the prepared LiFePO4/C were studied. A quadratic formula was obtained by response surface analysis between the discharge capacity of the prepared LiFePO4/C and the four parameters. The discharge capacity of the prepared LiFePO4/C depends more on the sintering temperature and sucrose amount than the other variables. The quadratic term of the four parameters, the sintering temperature, the sucrose amount and the interaction between the later two parameters have significant effects on the discharge capacity of the prepared LiFePO4/C. The obtained model reveals that the optimized LiFePO4/C preparation parameters are as follows:sintering temperature of 718℃, sucrose amount of 0.866 g?g?1 LiFePO4, 10.88 h sintering time and heating temperature of 105℃. Under these conditions, the actual discharge capacity of the prepared LiFePO4/C is 140.6mA?h?g?1, and this value does not significantly different from that predicted by the model (142.03 mA?h?g?1).