锂离子电池论文磷酸亚铁锂硬碳锂离子电池工艺及电化学性能研究报告.docx

精品名师归纳总结锂离子电池论文：磷酸亚铁锂 / 硬碳锂离子电池的工艺及电化学性能讨论【中文摘要】自从锂离子电池被胜利研制并商业化以来 , 锂离子电池以其循环寿命长、工作电压高、安全性好、无记忆效应等特点越来越受到人们的青睐和重视然而 , 锂离子电池电化学性能的好坏与其所使用的正负极材料、导电剂、粘结剂、电解液、隔膜等有着 亲密的关系磷酸亚铁锂 〔LiFePO4>因其具有原料丰富、比容量高、结构稳固、安全性好等优点成为了一种比较有潜力的锂离子电池正 极材料同时 , 可以作为锂离子电池负极材料的硬碳 〔hard carbon,HC>,由于其无规章的排序具有较高的容量、优良的循环性能和较低的造价等特性 , 使得人们对其产生了极大的爱好本文将 LiFePO4 与硬碳组合成 LiFePO4/HC电池, 从正极材料所用的导电剂和粘结剂等工艺方面对 LiFePO4/Li 半电池及 LiFePO4/HC全电池的电化学性能影响进行讨论 , 并将 LiFePO4/HC电池和 LiFePO4/石墨〔AGP-3>电池的电化学性能进行比较 , 得出如下结论： 1. 对于 LiFePO4/Li 半电池, 使用 Super P Li 做导电剂时 , 电池的电阻相对更小 , 在 0.2 C 和 1 C的放电倍率下 , 电池的放电平台都比使用乙炔黑做导电剂时更为平稳 ,且比容量更大。

在 1 C 放电倍率下经过 150 个循环后 , 电池容量的保持率要相对更稳固循环伏安测试说明所使用的 LiFePO4 材料本身的循环可逆性较好 , 这与 LiFePO4颗粒间存在的碳纳 M管提高了其导电性可能有很大的关系 2. 对于 LiFePO4/HC全电池 , 同样我们得出可编辑资料 -- -- -- 欢迎下载精品名师归纳总结使用 Super P Li 做导电剂时 , 电池的电阻相对更小且比容量更大倍率性能测试显示 , 使用 Super P Li 做导电剂时电池的倍率性能更 加优越, 但是, 可能由于所使用的粘结剂 PVDF粘结性能不够好 , 使得电池在 10 C 的放电倍率下比容量很低同时 , 与 LiFePO4/Li 半电池相比, 全电池的电阻值要小 , 放电曲线没有显现平台且在 1 C 放电倍率下循环 150 次后电池的容量保持率要高 3. 使用水性粘结剂 SBR 和油性粘结剂 PVDF制得 LiFePO4极片 , 将其与金属锂片组合成LiFePO4/Li 电池在 0.2 C 的放电倍率下 , 使用两种粘结剂体系电池的放电平台 〔 约 3.38 V> 都较为平稳 , 放电比容量基本相等 , 其中水性粘结剂 SBR体系其比容量稍低一些 , 当电池放电倍率为 1 C 时, 使用水性粘结剂 SBR时, 电池的首次和第 2 次放电比容量都比使用油性粘结剂 PVDF时要高。

从沟通阻抗和循环寿命测试我们得知 , 使用水性粘结剂时电池的阻抗值更小 , 其 Rct 值为 89.68 Ω, 在 1 C 的放电倍率下, 经过 150 个循环后 , 电池容量的保持率要相对更稳固 , 其保持率为 65%4. 使用两种粘结剂后 ,LiFePO4/HC 电池在 0.2 C 的放电倍率下, 油性粘结剂体系的 LiFePO4/HC电池的首次放电比容量要高于水性粘结剂体系 , 但随着循环的进行油性粘结剂体系的放电比容量会呈下降趋势 , 而水性粘结剂体系就会出现肯定的上升趋势当电池在1 C 的放电倍率下进行放电时 , 与半电池测试结果相同 , 水性粘结剂体系电池的放电比容量要高于油性粘结剂体系且容量保持率要好 , 保持率为 97.9%倍率性能测试显示 , 水性粘结剂体系电池的大倍率性能要好于油性粘结剂体系此外 , 使用水性粘结剂时电池的阻抗值更可编辑资料 -- -- -- 欢迎下载精品名师归纳总结小, 其 Rct 值为 5.08 Ω, 且无论哪种粘结剂全电池的阻抗值都要比半电池小 5. 使用硬碳做负极时电池的倍率性能要好 , 电池在 1 C 的充放电倍率下进行充放电时 ,LiFePO4/AGP-3 和 LiFePO4/HC电池的放电比容量值分别为 0.2 C 倍率下的 84.3%和 91.0%, 在 1 C 和 2 C 的放电倍率下 ,LiFePO4/AGP-3 电池的放电比容量要稍高于 LiFePO4/HC 电池, 但是当电池的放电倍率为 5 C 和 10 C 时,LiFePO4/HC 电池的放电比容量值却要高于 LiFePO4/AGP-3电池。

6. 电池使用硬碳和石墨材料做负极时阻抗值相差不大 ,LiFePO4/HC 电池的 Rct 值稍小一些1 C 的放电倍率下 ,LiFePO4/HC 电池的循环寿命要比LiFePO4/AGP-3电池长此外 , 与正负极材料的半电池相比 , 在 10 C 的放电倍率下 ,LiFePO4/HC 全电池的循环寿命要远远长于半电池 , 经过 2450 个循环后电池的放电比容量才降为首次的 60%英文摘要】 Since lithium ion batteries have beensuccessfully investigated and commercialized, they attract people ’s attention for their properties such as long cycling life, high voltage, security, no memory effort.However, the electrochemical performance of lithium ion battery is affinitive with its cathode and anode materials, conductive agent, binder, electrolyte, separator et al.Lithium iron phosphate 〔LiFePO4> has been considered as a promising lithium ion battery because of its rich raw materials, high capacity, stable structure, safety et al.可编辑资料 -- -- -- 欢迎下载精品名师归纳总结As well, hard carbon 〔HC> with an inordinance structure which can be used for an anode material of lithium ionbattery has been attracted people ’s interest for its highcapacity, excellent cycling performance and low cost et al. In this thesis, we have developed a lithium ion battery- LiFePO4/HC using LiFePO4 as cathode and hard carbon as anode to study the conductive agent and binder influence of the electrochemical properties of LiFePO4/Li half cell and LiFePO4/HC full cell. In addition, we compared the electrochemical performance of LiFePO4/HC battery andLiFePO4/graphite 〔AGP-3>. Through the experiments, we gotthe following conclusions:1. For LiFePO4/Li half cell, using Super P Li as conductive agent, the resistance of battery was smaller. At 0.2 C or 1 C rate, the discharge voltage plateau of the cell using Super P Li as the conductive agent was more stable than that of using acetylene black. After 150 cycles at 1 C rate, the capacity retention of the cell using Super P Li as conductive agentwas higher. Cyclic voltammetry indicated that the LiFePO4 material has a good cyclic reversibility, which may be caused by the good conductivity results from the carbon fibers among LiFePO4 particles.2. For LiFePO4/HC full cell,可编辑资料 -- -- -- 欢迎下载精品名师归纳总结we also got the conclusion that using Super P Li as conductive agent, the resistance of the cell was smaller and the capacity of it was higher. Rate performance test has shown that the cell using Super P Li as conductive had better rate performance, however, the discharge capacity of the cell was small at 10 C rate neither using Super P Li oracetylene black as conductive agent, which maybe due to the the unsatisfactory bond performance of the PVDF binder.Comparing with the LiFePO4/Li half cell, the resistance of the full cell was smaller and the capacity retention was higher after 150 cycles at 1 C rate.3. We have used a waterbinder 〔SBR> and an oiliness binder 〔PVDF> to make LiFePO4 cathode electrode, and assembled with lithium metal composing to LiFePO4Li lithium ion battery. Both of thewater-based binder system and the oil-based binder system, the discharge voltage plateau 〔about 3.38 V> of the c。