本文選題：鎳鈷錳酸鋰材料 + 成核�。� 參考：《哈爾濱工業(yè)大學》2017年碩士論文

【摘要】：隨著動力電池市場的迅猛發(fā)展,電池的正極材料逐漸成為產業(yè)化研究的主要方向之一,其中富鎳組分的三元鎳鈷錳811材料憑借高放電比容量(200 mAh g~(-1))、低成本的特點成為下一步產業(yè)化的熱點。目前三元NCM鎳鈷錳材料最為常見和成熟的合成方法是先使用共沉淀法合成三元材料前驅體,再混鋰高溫固相燒結,這種方法可以得到粒度分布可控、振實密度高的球型三元正極材料。目前經過多年的實驗室小規(guī)模研究,已基本探尋出控制材料振實密度和顆粒粒徑的影響條件,研究出溫度、pH值、氨/金屬進料比等關鍵因素對一次顆粒、堆積致密度及振實密度的作用規(guī)律,探索出了穩(wěn)定的合成工藝,合成出了高振實密度(ρ2.1 g cm~(-3))的前驅體材料,已經具備了放大化合成的條件。本論文從產業(yè)化角度出發(fā),使用共沉淀法進行合成放大研究,分別從晶體的成核與生長角度對鎳鈷錳酸鋰材料的前驅體——氫氧化鎳鈷錳材料的振實密度和顆粒粒徑進行研究。研究了放大化反應釜中,底液量對初級成核與團聚的影響,重點分析了攪拌槳葉、固液比、晶體粒度和攪拌速度對氫氧化鎳鈷錳材料的二次成核影響;研究了攪拌速度、攪拌槳葉、固液比和反應時間對二次顆粒生長的影響。在已有的實驗室小釜工藝基礎上,針對工藝放大后由攪拌問題帶來的不斷成核、振實密度低和顆粒粒徑變化等現(xiàn)象,設計新反應工藝,獲得了高振實(ρ=2.04 g cm~(-3))、小粒徑的前驅體材料,其倍率性能和循環(huán)性能都要明顯優(yōu)于商業(yè)材料。堿性過高是富鎳三元材料產業(yè)化面臨的一個重要問題,同時還影響電極材料的性能發(fā)揮,使用一種酸性的聚苯胺PANI進行洗滌處理可以有效的去除富鎳三元材料表面的堿性鋰殘余物,提高了活性材料的電導率和鋰離子擴散系數(shù),同時不對材料的晶體結構造成明顯改變,不會造成容量的損失,全面地提升了富鎳三元材料的循環(huán)性能和倍率性能。此外,在此基礎上包覆PANI還可以進一步提升富鎳三元材料的循環(huán)性能。
[Abstract]:With the rapid development of power battery market, the cathode material of battery has gradually become one of the main research directions of industrialization. Among them, nickel rich ternary Ni-Co-Mn 811 material with high discharge specific capacity of 200 mAh / g ~ (-1) has become the focus of industrialization in the next step because of its low cost. At present, the most common and mature synthesis method for ternary NCM materials is to synthesize ternary precursors by coprecipitation, and then to mix lithium with high temperature solid state sintering. The particle size distribution can be controlled by this method. Spherical ternary cathode material with high vibrational density. At present, after many years of small-scale laboratory research, the influence conditions of controlling material vibrational density and particle size have been basically explored, and the key factors such as temperature and pH value, ammonia / metal feed ratio and other key factors to primary particles have been studied. On the basis of the effect of stacking density and vibrational density, a stable synthetic process has been explored, and a precursor material with high vibrational density (蟻 2.1 g / cm ~ (-1) has been synthesized. The conditions for amplification synthesis have been obtained. In this paper, the coprecipitation method was used to study the synthesis amplification from the perspective of industrialization. The vibrational density and particle size of nickel cobalt manganese hydroxide precursor, nickel-cobalt manganese hydroxide, were studied from the point of view of crystal nucleation and growth respectively. The effect of the amount of base liquid on primary nucleation and agglomeration in a scale-up reactor was studied. The effects of stirring blade, solid-liquid ratio, crystal size and stirring speed on the secondary nucleation of nickel-cobalt-manganese hydroxide materials were analyzed. Effects of stirring blade, solid / liquid ratio and reaction time on secondary particle growth. Based on the existing laboratory reactor process, a new reaction process was designed to solve the problems of continuous nucleation, low vibrational density and particle size change caused by agitation. The ratio and cyclic properties of the precursor materials with high vibrational strength (蟻 ~ (2. 04) g / cm ~ (-1)) and small particle size are obviously superior to those of commercial materials. Too high alkalinity is an important problem in the industrialization of nickel rich ternary materials, and it also affects the performance of electrode materials. Using an acidic Polyaniline PANI for washing can effectively remove the alkaline lithium residue on the surface of nickel rich ternary material, and improve the conductivity and the diffusion coefficient of lithium ion of the active material. At the same time, the crystal structure of the material is not obviously changed, and the loss of capacity will not be caused. The cycling performance and the rate performance of the nickel rich ternary material are improved completely. In addition, coating PANI on this basis can further improve the cycling performance of nickel rich ternary materials.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM912

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本文編號：1825920