TWI728447B

TWI728447B - LiFePO4 PRECURSOR FOR MANUFACTURING ELECTRODE MATERIAL OF Li-ION BATTERY AND METHOD FOR MANUFACTURING THE SAME

Info

Publication number: TWI728447B
Application number: TW108130943A
Authority: TW
Inventors: 周麗新; 胡力文; 潘俊羽; 洪紹庭; 吳貴兆
Original assignee: 國立清華大學
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2021-05-21
Also published as: TW202108500A

Abstract

A LiFePO₄ precursor for manufacturing an electrode material of a Li-ion battery and a method for manufacturing the same are disclosed. The LiFePO₄ precursor of the present disclosure can be represented by the following formula (I): LiFe₍ _1-a) M_a PO₄ (I) wherein M and a are defined in the specification, the LiFePO₄ precursor does not have an olivine structure, and the LiFePO₄ precursor is powders constituted by plural flakes.

Description

製備鋰離子電池電極材料的磷酸鋰鐵前驅物及其製備方法Lithium iron phosphate precursor for preparing electrode material of lithium ion battery and preparation method thereof

本揭露係關於一種製備鋰離子電池電極材料的磷酸鋰鐵前驅物及其製備方法。更具體地，本揭露提供一種製備鋰離子電池電極材料的新穎磷酸鋰鐵前驅物及其製備方法。The disclosure relates to a lithium iron phosphate precursor for preparing electrode materials of lithium ion batteries and a preparation method thereof. More specifically, the present disclosure provides a novel lithium iron phosphate precursor for preparing electrode materials of lithium ion batteries and a preparation method thereof.

隨著各種可攜式電子裝置之發展，對於能量儲存技術的關注也日益漸增。而電池為這些可攜式電子裝置主要的電力來源。在商用電池中，小型二次電池為可攜式電子產品(尤其是手機、筆記型電腦等)的主要電力來源。此外，二次電池不僅應用至可攜式電子裝置外，亦應用在電動車上。With the development of various portable electronic devices, attention to energy storage technology is also increasing. The battery is the main source of power for these portable electronic devices. Among commercial batteries, small secondary batteries are the main power source for portable electronic products (especially mobile phones, notebook computers, etc.). In addition, secondary batteries are not only applied to portable electronic devices, but also to electric vehicles.

於已開發的二次電池中，以1990年所開發的鋰二次電池（或稱為鋰離子電池）是目前最廣泛使用的電池。早期之鋰二次電池係採用鈷酸鋰（LiCoO₂ ）做為陰極材料。鈷酸鋰具有高工作電壓、穩定充放電壓之優點，故使用鈷酸鋰做為陰極材料的二次電池大量應用在可攜式產品。而後，更開發出以橄欖石結構磷酸鋰鐵（LiFePO₄ ）和尖晶石結構錳酸鋰（LiMn₂ O₄ ）做為鋰二次電池之陰極材料。相較於以鈷酸鋰做為陰極材料，當以磷酸鋰鐵和錳酸鋰做為二次電池的陰極材料時，可改善電池安全性、提升充放電次數、及進一步降低成本等優點。Among the secondary batteries that have been developed, the lithium secondary battery (or lithium ion battery) developed in 1990 is currently the most widely used battery. Early lithium secondary batteries used lithium cobalt oxide (LiCoO ₂ ) as the cathode material. Lithium cobalt oxide has the advantages of high working voltage and stable charging and discharging voltage. Therefore, secondary batteries using lithium cobalt oxide as a cathode material are widely used in portable products. Later, the olivine structure lithium iron phosphate (LiFePO ₄ ) and spinel structure lithium manganate (LiMn ₂ O ₄ ) were developed as cathode materials for lithium secondary batteries. Compared with lithium cobalt oxide as the cathode material, when lithium iron phosphate and lithium manganate are used as the cathode material of the secondary battery, it can improve battery safety, increase the number of charge and discharge, and further reduce costs.

雖然以錳酸鋰做為陰極材料的電池具有成本低、安全性佳等優勢，但在深度放電時易發生姜-泰勒(Jahn-Teller)效應，導致尖晶石結構的錳酸鋰崩壞。在這種情況下，電池循環性會進一步降低。當以磷酸鋰鐵做為電池的陰極材料時，電池也擁有低成本和安全性高等特性。此外，磷酸鋰鐵之理論電容量甚至比錳酸鋰更高，故以磷酸鋰鐵製備的電池可用於需大電流及高功率之裝置上。另外，磷酸鋰鐵為無毒且環保材料，且高溫特性佳。於是，磷酸鋰鐵被視為一種優異的鋰電池陰極材料。目前以磷酸鋰鐵做為陰極材料之鋰離子電池，其平均放電電壓為3.2~3.4 V vs. Li⁺ /Li。Although batteries using lithium manganate as the cathode material have the advantages of low cost and good safety, the Jahn-Teller effect is prone to occur during deep discharge, which causes the spinel structure of lithium manganate to collapse. In this case, the battery cycle performance will be further reduced. When lithium iron phosphate is used as the cathode material of the battery, the battery also has the characteristics of low cost and high safety. In addition, the theoretical capacity of lithium iron phosphate is even higher than that of lithium manganate, so batteries made of lithium iron phosphate can be used in devices that require high current and high power. In addition, lithium iron phosphate is a non-toxic and environmentally friendly material, and has good high-temperature characteristics. Therefore, lithium iron phosphate is regarded as an excellent cathode material for lithium batteries. Currently, lithium-ion batteries using lithium iron phosphate as the cathode material have an average discharge voltage of 3.2~3.4 V vs. Li ⁺ /Li.

常見之鋰離子電池結構係包含：一陰極、一陽極、一隔離板、及一含鋰之電解質。鋰離子電池係依循鋰之嵌埋-脫嵌機制進行電池之充放電，其充放電機制係如下式(I)及(II)所示。充電：LiFePO₄ - x Li⁺ - xe^- → xFePO₄ + (1 - x)LiFePO₄ (I) 放電：FePO₄ + x Li⁺ +xe^- → x LiFePO₄ + (1-x)FePO₄ (II)The structure of a common lithium ion battery includes: a cathode, an anode, a separator, and an electrolyte containing lithium. Lithium-ion batteries follow the lithium embedding-de-embedding mechanism for battery charging and discharging, and the charging and discharging mechanism is shown in the following formulas (I) and (II). _{^{Charging: LiFePO 4 - x Li + -}} xe - → xFePO 4 + (1 - x) LiFePO 4 (I) _{^{Discharge: FePO 4 + x Li + +}} xe - → x LiFePO 4 + (1-x) FePO 4 (II )

當電池充電時，鋰離子會從磷酸鋰鐵結構脫離；而當放電時，鋰離子會再進入磷酸鐵（FePO₄ ）結構。於是，鋰離子電池之充放電過程是一個磷酸鋰鐵/磷酸鐵兩相過程。然而，鋰離子在磷酸鋰鐵和磷酸鐵中擴散速率相當低，故一般係於陰極材料中添加金屬摻雜物，以提升鋰離子擴散速率。此外，目前使用之磷酸鋰鐵的鋰離子擴散距離較長，故磷酸鋰鐵之導電度較差。於是，一般係藉由在磷酸鋰鐵粉末塗覆碳以增加其導電度，藉此以提升電池之充放電效率。然而，當磷酸鋰鐵粉末摻雜金屬添加物或塗覆碳時，磷酸鋰鐵粉末的製造過程變得較為複雜。在這種情況下，鋰離子電池之成本也隨之增加。When the battery is charged, lithium ions will be separated from the lithium iron phosphate structure; when discharged, the lithium ions will re-enter the iron phosphate (FePO ₄ ) structure. Therefore, the charging and discharging process of lithium-ion batteries is a two-phase lithium iron phosphate/iron phosphate process. However, the diffusion rate of lithium ions in lithium iron phosphate and iron phosphate is quite low, so metal dopants are generally added to the cathode material to increase the lithium ion diffusion rate. In addition, the lithium iron phosphate currently used has a long lithium ion diffusion distance, so the conductivity of lithium iron phosphate is poor. Therefore, generally, the lithium iron phosphate powder is coated with carbon to increase its conductivity, thereby improving the charging and discharging efficiency of the battery. However, when the lithium iron phosphate powder is doped with metal additives or coated with carbon, the manufacturing process of the lithium iron phosphate powder becomes more complicated. In this case, the cost of lithium-ion batteries has also increased.

現今多採用固態法製備磷酸鋰鐵粉末。然而，固態法之燒結溫度卻與產物性質極為相關。當燒結溫度在700^o C以下，所有原料要充分混合，若原料沒有充分混合，則會在磷酸鋰鐵粉末出現Fe³⁺ 雜質相；但當燒結溫度低於600^o C，磷酸鋰鐵粉末之平均粒徑將小於30 μm。然而，若燒結溫度一提高，磷酸鋰鐵粉末之平均粒徑就大於30 μm，而須再加入後續研磨及過篩的過程使粉末粒徑介於1 μm到10 μm之間。於是，固態法不易製作出具有奈米尺寸之磷酸鋰鐵粉末。Nowadays, solid-state methods are often used to prepare lithium iron phosphate powder. However, the sintering temperature of the solid-state method is extremely related to the properties of the product. When the sintering temperature is below 700 ^o C, all the raw materials must be fully mixed. If the raw materials are not fully mixed, Fe ³⁺ impurity phases will appear in the lithium iron phosphate powder; but when the sintering temperature is lower than 600 ^o C, the lithium iron phosphate powder The average particle size will be less than 30 μm. However, if the sintering temperature increases, the average particle size of the lithium iron phosphate powder is greater than 30 μm, and subsequent grinding and sieving processes must be added to make the powder particle size between 1 μm and 10 μm. Therefore, the solid-state method is not easy to produce lithium iron phosphate powder with nanometer size.

因此，目前亟需發展出一種以簡便方法製作之鋰離子電池用之奈米尺寸陰極材料，以提升電池之充放電效率外，更降低其製作成本。Therefore, there is an urgent need to develop a nano-sized cathode material for lithium-ion batteries that can be fabricated by a simple method to improve the charging and discharging efficiency of the battery and reduce the production cost.

本揭露之目的係提供一種製備鋰離子電池電極材料的磷酸鋰鐵前驅物及其製備方法。The purpose of this disclosure is to provide a lithium iron phosphate precursor for preparing a lithium ion battery electrode material and a preparation method thereof.

本揭露之製備鋰離子電池電極材料的磷酸鋰鐵前驅物可由下列式(I)表示： LiFe₍ _1-a) M_a PO₄ (I) 其中M包括至少一選自由錳、鉻、鈷、銅、鎳、釩、鉬、鈦、鋅、鋯、鎝、釕、銠、鈀、銀、鎘、鉑、金、鋁、鎵、銦、鈹、鎂、鈣、鍶、硼、及鈮所組成之群組之金屬，0 ≤ a > 0.5，該磷酸鋰鐵前驅物不具有橄欖石結構，且該磷酸鋰鐵前驅物係由複數薄片所構成之粉末。The lithium iron phosphate precursor for preparing the electrode material of the lithium ion battery of the present disclosure can be represented by the following formula (I): LiFe ₍ _1-a) M _a PO ₄ (I) where M includes at least one selected from manganese, chromium, cobalt, and copper , Nickel, vanadium, molybdenum, titanium, zinc, zirconium, tectonium, ruthenium, rhodium, palladium, silver, cadmium, platinum, gold, aluminum, gallium, indium, beryllium, magnesium, calcium, strontium, boron, and niobium Group of metals, 0 ≤ a> 0.5, the lithium iron phosphate precursor does not have an olivine structure, and the lithium iron phosphate precursor is a powder composed of a plurality of flakes.

本揭露之製備前述磷酸鋰鐵前驅物之製備方法可包括下列步驟：提供一混合有機溶液，其包括鋰、鐵、及磷，其中該混合有機溶液中所含的鋰係源自一含鋰前驅物或一含磷和含鋰前驅物，該混合有機溶液中所含的鐵係源自一含鐵前驅物或一含磷和含鐵前驅物，而該混合有機溶液中所含的磷係源自一含磷前驅物、一含磷和含鋰前驅物、或一含磷和含鐵前驅物；以及以回流方式加熱該混合有機溶液至一預定溫度且維持在該預定溫度一預定時間，以獲得該磷酸鋰鐵前驅物。The method for preparing the aforementioned lithium iron phosphate precursor of the present disclosure may include the following steps: providing a mixed organic solution including lithium, iron, and phosphorus, wherein the lithium contained in the mixed organic solution is derived from a lithium-containing precursor Or a phosphorus-containing and lithium-containing precursor, the iron contained in the mixed organic solution is derived from an iron-containing precursor or a phosphorus-containing and iron-containing precursor, and the phosphorus-containing source in the mixed organic solution From a phosphorus-containing precursor, a phosphorus-containing and lithium-containing precursor, or a phosphorus-containing and iron-containing precursor; and the mixed organic solution is heated to a predetermined temperature in a reflux manner and maintained at the predetermined temperature for a predetermined time, to The lithium iron phosphate precursor is obtained.

本揭露更提供一種製備鋰離子電池之磷酸鋰鐵電極材料的方法，其包括：提供前述磷酸鋰鐵前驅物，且熱處理該磷酸鋰鐵前驅物，以獲得該磷酸鋰鐵電極材料。The present disclosure further provides a method for preparing a lithium iron phosphate electrode material for a lithium ion battery, which includes: providing the aforementioned lithium iron phosphate precursor, and heat-treating the lithium iron phosphate precursor to obtain the lithium iron phosphate electrode material.

於本揭露中，包含在該有機混合溶液的前驅物彼此反應，以形成該磷酸鋰鐵前驅物，其為用於形成鋰離子電池磷酸鋰鐵電極材料的一前驅物。於此，本揭露之磷酸鋰鐵前驅物之結晶結構不同於用於鋰離子電池的傳統磷酸鋰鐵粉末。更具體地，本揭露之磷酸鋰鐵前驅物不具有橄欖石結構。In the present disclosure, the precursors contained in the organic mixed solution react with each other to form the lithium iron phosphate precursor, which is a precursor for forming the lithium iron phosphate electrode material of the lithium ion battery. Here, the crystalline structure of the lithium iron phosphate precursor disclosed in the present disclosure is different from the traditional lithium iron phosphate powder used in lithium ion batteries. More specifically, the lithium iron phosphate precursor of the present disclosure does not have an olivine structure.

此外，當本揭露之磷酸鋰鐵前驅物經熱處理時，可獲得鋰離子電池的磷酸鋰鐵電極材料。於此，在熱處理後，可維持磷酸鋰鐵前驅物的形狀，其意味著獲得的磷酸鋰鐵電極材料具有與磷酸鋰鐵前驅物相同的形狀。於本揭露中，磷酸鋰鐵前驅物為具有薄片之粉末，故獲得的磷酸鋰鐵電極材料也為具有薄厚度薄片之粉末。因獲得的磷酸鋰鐵電極材料的厚度非常薄，所以鋰離子之嵌埋和脫嵌路徑可大幅縮短，而鋰離子之擴散速率可進一步提高。當獲得的磷酸鋰鐵電極材料做為鋰離子電池的陰極材料時，由於短的鋰離子擴散路徑而可提升鋰離子電池之充放電效率。In addition, when the lithium iron phosphate precursor of the present disclosure is heat-treated, a lithium iron phosphate electrode material for a lithium ion battery can be obtained. Here, after the heat treatment, the shape of the lithium iron phosphate precursor can be maintained, which means that the obtained lithium iron phosphate electrode material has the same shape as the lithium iron phosphate precursor. In this disclosure, the lithium iron phosphate precursor is a powder with flakes, so the obtained lithium iron phosphate electrode material is also a powder with thin flakes. Since the thickness of the obtained lithium iron phosphate electrode material is very thin, the embedding and de-intercalation path of lithium ions can be greatly shortened, and the diffusion rate of lithium ions can be further improved. When the obtained lithium iron phosphate electrode material is used as the cathode material of the lithium ion battery, the charging and discharging efficiency of the lithium ion battery can be improved due to the short lithium ion diffusion path.

於本揭露中，磷酸鋰鐵前驅物可包括具有不同結晶的粉末。於本揭露中，磷酸鋰鐵前驅物可包括一非晶區和一結晶區。於此，非晶區的含量大於結晶區的含量。例如，非晶區的含量對結晶區的含量之比例可介於10:1至2:1之間、9:1至2:1之間、8:1至2:1之間、7:1至2:1之間、6:1至2:1之間、5:1至2:1之間、10:1至3:1之間、9:1至3:1之間、8:1至3:1之間、7:1至3:1之間、6:1至3:1之間、或5:1至3:1之間。於本揭露一實施例中，該比例約為4:1，但本揭露不限於此。此外，在磷酸鋰鐵前驅物中非結晶區和結晶區的分布不特別限制。例如，多個結晶區可分布在非結晶區中。In the present disclosure, the lithium iron phosphate precursor may include powders with different crystals. In this disclosure, the lithium iron phosphate precursor may include an amorphous region and a crystalline region. Here, the content of the amorphous region is greater than the content of the crystalline region. For example, the ratio of the content of the amorphous region to the content of the crystalline region may be between 10:1 to 2:1, 9:1 to 2:1, 8:1 to 2:1, 7:1 To 2:1, 6:1 to 2:1, 5:1 to 2:1, 10:1 to 3:1, 9:1 to 3:1, 8:1 To 3:1, 7:1 to 3:1, 6:1 to 3:1, or 5:1 to 3:1. In an embodiment of the present disclosure, the ratio is about 4:1, but the present disclosure is not limited to this. In addition, the distribution of amorphous regions and crystalline regions in the lithium iron phosphate precursor is not particularly limited. For example, a plurality of crystalline regions may be distributed in the amorphous region.

於本揭露中，結晶區可包括至少一選自由C₂ H₄ Li₄ O₇ P₂ ·H₂ O、Fe₃ H₉ (PO₄ )₆ ·6H₂ O、Fe₂ Fe(P₂ O₇ )₂ 、FeLiO₂ 、Li₂ Fe₂ O₄ 、FePO₄ 、C₆ H₆ FeO₈ ·2H₂ O、FePO₄ (H₂ O)₂ 、Li₂ O₂ 、Li、及Fe₂ O(PO₄ )所組成之群組。於本揭露另一實施例中，結晶區更可包括至少一選自由Fe₃ O₄ 、Fe₃ PO₇ 、Fe₃ Fe₄ (PO₄ )₆ 、及C₂ HLiO₄ ·H₂ O所組成之群組。In the present disclosure, the crystalline region may include at least one selected from C ₂ H ₄ Li ₄ O ₇ P ₂ ·H ₂ O, Fe ₃ H ₉ (PO ₄ ) ₆ ·6H ₂ O, Fe ₂ Fe(P ₂ O ₇ ) ₂ , FeLiO ₂ , Li ₂ Fe ₂ O ₄ , FePO ₄ , C ₆ H ₆ FeO ₈ 2H ₂ O, FePO ₄ (H ₂ O) ₂ , Li ₂ O ₂ , Li, and Fe ₂ O (PO ₄ ). In another embodiment of the present disclosure, the crystalline region may further include at least one selected from Fe ₃ O ₄ , Fe ₃ PO ₇ , Fe ₃ Fe ₄ (PO ₄ ) ₆ , and C ₂ HLiO ₄ ·H ₂ O Group.

於本揭露中，磷酸鋰鐵前驅物的X光繞射圖譜可具有在接近19.37^o 、21.47^o 、24.11^o 、25.95^o 、32.35^o 、35^o 、36.46^o 、及43.83^o 的2θ角的特徵峰。於本揭露另一實施例中，磷酸鋰鐵前驅物的X光繞射圖譜可更具有在接近18.3^o 、28.91^o 、及30.05^o 的2θ角的特徵峰。須注意的是，本揭露之磷酸鋰鐵前驅物之X光繞射圖譜不同於具有橄欖石結構的磷酸鋰鐵粉末。In the present disclosure, X-ray diffraction pattern of the lithium iron phosphate precursor may have a close ^{^{^{19.37 o, 21.47 o, 24.11 o}}} , 25.95 o, 32.35 o, 35 o, 36.46 o, and the characteristic peaks of angle 2θ of 43.83 ^o . In another embodiment of the present disclosure, X-ray diffraction pattern of the lithium iron phosphate precursor can be more close to 18.3 ^{^o,} 28.91 ^o, and the characteristic peaks of angle 2θ of 30.05 ^o. It should be noted that the X-ray diffraction pattern of the lithium iron phosphate precursor disclosed in the present disclosure is different from the lithium iron phosphate powder having an olivine structure.

於本揭露中，薄片的磷酸鋰鐵前驅物粉末及由熱處理該磷酸鋰鐵前驅物粉末所獲得的磷酸鋰鐵粉末可分別具有介於800 nm至5 μm之間的直徑。此外，薄片的磷酸鋰鐵前驅物粉末及熱處理該磷酸鋰鐵前驅物粉末所獲得的該磷酸鋰鐵粉末可分別具有複數薄片。於此，每一薄片的長度不特別限制。例如，每一薄片的長度可分別介於400 nm至5000 nm之間、400 nm至3000 nm之間、400 nm至2000 nm之間、400 nm至1500 nm之間、400 nm至1300 nm之間、400 nm至1100 nm之間、600 nm至5000 nm之間、600 nm至3000 nm之間、600 nm至2000 nm之間、600 nm至1500 nm之間、600 nm至1300 nm之間、600 nm至1100 nm之間、700 nm至5000 nm之間、700 nm至3000 nm之間、700 nm至2000 nm之間、700 nm至1500 nm之間、700 nm至1300 nm之間、或700 nm至1100 nm之間。此外，每一薄片的厚度也不特別限制。例如，每一薄片的厚度可分別介於1 nm至50 nm之間、1 nm至40 nm之間、1 nm至30 nm之間、1 nm至20 nm之間、1 nm至15 nm之間、3 nm至50 nm之間、3 nm至40 nm之間、3 nm至30 nm之間、3 nm至20 nm之間、3 nm至15 nm之間、4 nm至50 nm之間、4 nm至40 nm之間、4 nm至30 nm之間、4 nm至20 nm之間、4 nm至15 nm之間、5 nm至50 nm之間、5 nm至40 nm之間、5 nm至30 nm之間、5 nm至20 nm之間、5 nm至15 nm之間、或5 nm至14 nm之間。In the present disclosure, the flake lithium iron phosphate precursor powder and the lithium iron phosphate powder obtained by heat-treating the lithium iron phosphate precursor powder may each have a diameter between 800 nm and 5 μm. In addition, the lithium iron phosphate precursor powder of the flakes and the lithium iron phosphate powder obtained by heat-treating the lithium iron phosphate precursor powder may each have a plurality of flakes. Here, the length of each sheet is not particularly limited. For example, the length of each slice can be between 400 nm and 5000 nm, between 400 nm and 3000 nm, between 400 nm and 2000 nm, between 400 nm and 1500 nm, and between 400 nm and 1300 nm. , 400 nm to 1100 nm, 600 nm to 5000 nm, 600 nm to 3000 nm, 600 nm to 2000 nm, 600 nm to 1500 nm, 600 nm to 1300 nm, 600 nm Between nm and 1100 nm, between 700 nm and 5000 nm, between 700 nm and 3000 nm, between 700 nm and 2000 nm, between 700 nm and 1500 nm, between 700 nm and 1300 nm, or 700 nm To 1100 nm. In addition, the thickness of each sheet is not particularly limited. For example, the thickness of each slice can be between 1 nm and 50 nm, between 1 nm and 40 nm, between 1 nm and 30 nm, between 1 nm and 20 nm, and between 1 nm and 15 nm. , 3 nm to 50 nm, 3 nm to 40 nm, 3 nm to 30 nm, 3 nm to 20 nm, 3 nm to 15 nm, 4 nm to 50 nm, 4 Between nm and 40 nm, between 4 nm and 30 nm, between 4 nm and 20 nm, between 4 nm and 15 nm, between 5 nm and 50 nm, between 5 nm and 40 nm, between 5 nm and Between 30 nm, 5 nm to 20 nm, 5 nm to 15 nm, or 5 nm to 14 nm.

於本揭露中，當磷酸鋰鐵前驅物粉末和由熱處理該磷酸鋰鐵前驅物粉末所獲得的磷酸鋰鐵粉末分別具有複數薄片時，薄片可聚集形成一花朵狀形狀或層壓形成一頁岩狀形狀。此外，薄片的其中一者的一端可連接至薄片的另一者的一端。In this disclosure, when the lithium iron phosphate precursor powder and the lithium iron phosphate powder obtained by heat-treating the lithium iron phosphate precursor powder each have a plurality of flakes, the flakes can be aggregated to form a flower-like shape or laminated to form a shale-like shape. shape. In addition, one end of one of the sheets may be connected to one end of the other of the sheets.

於本揭露中，製備磷酸鋰鐵前驅物的方法可更包括透過一研磨製程以在該磷酸鋰鐵前驅物上塗覆一碳源以在該粉末上形成一碳層的步驟。故本揭露之磷酸鋰鐵前驅物粉末更可塗覆有一碳層。此外，也可在透過研磨製程以在磷酸鋰鐵前驅物上塗覆碳源的步驟中添加一催化劑。催化劑可例如為二茂鐵，但本揭露不限於此。於此，研磨製程可為一球磨法，但本揭露不限於此。於此，碳源的實例不特別限制，而可為任何糖（如蔗糖）、硬脂酸、檸檬酸、月桂酸(lauric acid)、聚苯乙烯、聚苯乙烯球（PS球）、或維生素C（L-抗壞血酸）。此外，碳源的添加量可為磷酸鋰鐵前驅物粉末重量的0.1 wt%至40 wt%之間。於本揭露一實施例中，碳源的添加量可為磷酸鋰鐵前驅物粉末重量的2.5 wt%至30 wt%之間。於本揭露另一實施例中，碳源的添加量可為磷酸鋰鐵前驅物粉末重量的5 wt%至20 wt%之間。In the present disclosure, the method for preparing the lithium iron phosphate precursor may further include a step of coating a carbon source on the lithium iron phosphate precursor through a grinding process to form a carbon layer on the powder. Therefore, the lithium iron phosphate precursor powder disclosed in the present disclosure can be coated with a carbon layer. In addition, a catalyst can also be added in the step of coating the lithium iron phosphate precursor with a carbon source through the grinding process. The catalyst may be, for example, ferrocene, but the present disclosure is not limited thereto. Here, the grinding process can be a ball milling method, but the disclosure is not limited to this. Here, examples of the carbon source are not particularly limited, but can be any sugar (such as sucrose), stearic acid, citric acid, lauric acid, polystyrene, polystyrene balls (PS balls), or vitamins. C (L-ascorbic acid). In addition, the addition amount of the carbon source may be between 0.1 wt% and 40 wt% of the weight of the lithium iron phosphate precursor powder. In an embodiment of the present disclosure, the addition amount of the carbon source may be between 2.5 wt% and 30 wt% of the weight of the lithium iron phosphate precursor powder. In another embodiment of the present disclosure, the addition amount of the carbon source may be between 5 wt% and 20 wt% of the weight of the lithium iron phosphate precursor powder.

於本揭露之方法中，可在混合有機溶液中進一步添加少量的一含金屬化合物，而在磷酸鋰鐵前驅物中的摻雜金屬可使由熱處理磷酸鋰鐵前驅物粉末所獲得的磷酸鋰鐵粉末之導電度提升。於此，摻雜金屬可為至少一選自由錳、鉻、鈷、銅、鎳、釩、鉬、鈦、鋅、鋯、鎝、釕、銠、鈀、銀、鎘、鉑、金、鋁、鎵、銦、鈹、鎂、鈣、鍶、硼、及鈮所組成之群組。此外，含金屬化合物可為摻雜金屬的硫酸鹽、碳酸鹽、硝酸鹽、草酸鹽、乙酸鹽、氯化物、溴化物、或碘化物。於本揭露一實施例中，含金屬化合物為摻雜金屬的硫酸鹽。於本揭露另一實施例中，含金屬化合物為錳、鉻、鈷、銅、鎳、鋅、鋁、或鎂之硫酸鹽。故於本揭露中，在式(I)中的M可為選自由錳、鉻、鈷、銅、鎳、釩、鉬、鈦、鋅、鋯、鎝、釕、銠、鈀、銀、鎘、鉑、金、鋁、鎵、銦、鈹、鎂、鈣、鍶、硼、及鈮所組成之群組。於本揭露一實施例中，在式(I)中的M可為一個或多個選自由錳、鉻、鈷、銅、鎳、鋅、鋁、及鎂所組成之群組的金屬。於本揭露另一實施例中，在式(I)中的M可為一個或多個選自由錳、銅、鋅、鋁、鎳、及鎂所組成之群組的金屬。In the method disclosed in the present disclosure, a small amount of a metal-containing compound can be further added to the mixed organic solution, and the doped metal in the lithium iron phosphate precursor can be the lithium iron phosphate obtained by heat-treating the lithium iron phosphate precursor powder The electrical conductivity of the powder is improved. Here, the doping metal can be at least one selected from the group consisting of manganese, chromium, cobalt, copper, nickel, vanadium, molybdenum, titanium, zinc, zirconium, tectonium, ruthenium, rhodium, palladium, silver, cadmium, platinum, gold, aluminum, The group consisting of gallium, indium, beryllium, magnesium, calcium, strontium, boron, and niobium. In addition, the metal-containing compound may be metal-doped sulfate, carbonate, nitrate, oxalate, acetate, chloride, bromide, or iodide. In an embodiment of the present disclosure, the metal-containing compound is a metal-doped sulfate. In another embodiment of the present disclosure, the metal-containing compound is a sulfate of manganese, chromium, cobalt, copper, nickel, zinc, aluminum, or magnesium. Therefore, in the present disclosure, M in formula (I) can be selected from manganese, chromium, cobalt, copper, nickel, vanadium, molybdenum, titanium, zinc, zirconium, tectonium, ruthenium, rhodium, palladium, silver, cadmium, The group consisting of platinum, gold, aluminum, gallium, indium, beryllium, magnesium, calcium, strontium, boron, and niobium. In an embodiment of the present disclosure, M in formula (I) can be one or more metals selected from the group consisting of manganese, chromium, cobalt, copper, nickel, zinc, aluminum, and magnesium. In another embodiment of the present disclosure, M in formula (I) can be one or more metals selected from the group consisting of manganese, copper, zinc, aluminum, nickel, and magnesium.

於本揭露之方法中，含鋰前驅物可為至少一選自由LiOH、Li₂ CO₃ 、LiNO₃ 、CH₃ COOLi、Li₂ C₂ O₄ 、Li₂ SO₄ 、LiCl、LiBr、及LiI所組成之群組；含鐵前驅物可為至少一選自由FeCl₂ 、FeBr₂ 、FeI₂ 、FeSO₄ 、(NH₄ )₂ Fe(SO₄ )₂ 、Fe(NO₃ )₂ 、FeC₂ O₄ 、(CH₃ COO)₂ Fe、及FeCO₃ 所組成之群組；含磷前驅物可為至少一選自由H₃ PO₄ 、NaH₂ PO₄ 、Na₂ HPO₄ 、Mg₃ (PO₄ )₂ 、及NH₄ H₂ PO₄ 所組成之群組；含磷和含鋰前驅物可為至少一選自由LiH₂ PO₄ 、Li₂ HPO₄ 、及Li₃ PO₄ 所組成之群組；而含磷和含鐵前驅物可為至少一選自由Fe₃ (PO₄ )₂ 、及FePO₄ 所組成之群組。此外，混合有機溶液不僅可包含前驅物外，還可包含其他添加劑（諸如界面活性劑、分散劑、聚合物電解質、及穩定劑），其可促進合成反應或前驅物的溶解。於此，界面活性劑的實例可為十六烷基三甲基溴化銨（CTAB）、十二烷基苯磺酸鈉（SDBS）、十二烷基硫酸鈉（SDS）、或辛基酚乙氧基化物（Triton-X100）；分散劑的實例可為十二烷基硫酸鉀、十二烷基硫酸銨、十二烷基硫酸鈣、十二烷基硫酸鈉、十二烷基硫酸銅、十二烷基硫酸鈉、十四烷基硫酸鈉、十六烷基硫酸鈉、十二烷基苯磺酸鈉、十二烷基苯磺酸鎂、十二烷基磺酸鈉、十二烷基磺酸鎂、癸基磺酸鈉、或癸基硫酸鈉；高分子電解質的實例可為聚乙烯吡咯烷酮（PVP）、過氧乙酸（PAA）、聚乙烯亞胺（PEI）、或聚丙烯酰胺（PAM）；穩定劑的實例可為聚乙烯醇（PVA）、或聚乙酸乙烯酯（PVAc）。添加劑可控制粉末的結晶尺寸和優選生長方向。此外，添加劑可單獨或兩種或多種添加劑一起使用。In the method of the present disclosure, the lithium-containing precursor may be at least one selected from LiOH, Li ₂ CO ₃ , LiNO ₃ , CH ₃ COOLi, Li ₂ C ₂ O ₄ , Li ₂ SO ₄ , LiCl, LiBr, and LiI. The iron-containing precursor can be at least one selected from FeCl ₂ , FeBr ₂ , FeI ₂ , FeSO ₄ , (NH ₄ ) ₂ Fe(SO ₄ ) ₂ , Fe(NO ₃ ) ₂ , FeC ₂ O ₄ , (CH ₃ COO) ₂ Fe, and FeCO ₃ ; the phosphorus-containing precursor can be at least one selected from H ₃ PO ₄ , NaH ₂ PO ₄ , Na ₂ HPO ₄ , Mg ₃ (PO ₄ ) ₂ , And NH ₄ H ₂ PO ₄ ; the phosphorus-containing and lithium-containing precursor can be at least one selected from the group consisting of LiH ₂ PO ₄ , Li ₂ HPO ₄ , and Li ₃ PO ₄ ; and The phosphorus and iron-containing precursor can be at least one selected from the group consisting of _{Fe 3} (PO ₄ ) ₂ and FePO _4. In addition, the mixed organic solution may not only contain the precursors, but also other additives (such as surfactants, dispersants, polymer electrolytes, and stabilizers), which can promote the synthesis reaction or the dissolution of the precursors. Here, examples of the surfactant may be cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzene sulfonate (SDBS), sodium dodecylsulfate (SDS), or octylphenol Ethoxylate (Triton-X100); examples of dispersants can be potassium lauryl sulfate, ammonium lauryl sulfate, calcium lauryl sulfate, sodium lauryl sulfate, copper lauryl sulfate , Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium dodecyl benzene sulfonate, magnesium dodecyl benzene sulfonate, sodium dodecyl sulfonate, dodecyl sulfate Magnesium alkyl sulfonate, sodium decyl sulfonate, or sodium decyl sulfate; examples of polymer electrolytes can be polyvinylpyrrolidone (PVP), peroxyacetic acid (PAA), polyethyleneimine (PEI), or polypropylene Amide (PAM); examples of stabilizers can be polyvinyl alcohol (PVA), or polyvinyl acetate (PVAc). Additives can control the crystal size and preferred growth direction of the powder. In addition, the additives may be used alone or in combination of two or more additives.

於本揭露之方法中，在混合有機溶液中的有機溶劑不特別限制，而可為任何多元醇有機溶劑。例如，有機溶劑可為至少一選自由乙二醇(EG)、二甘醇(DEG)、甘油、三甘醇(TEG)、四甘醇(TTEG)、聚乙二醇(PEG)、二甲基亞碸(DMSO)、及N,N-二甲基甲醯胺(DMF)所組成之群組。於本揭露一實施例中，有機溶劑為DEG、甘油、或其組合。In the method of the present disclosure, the organic solvent in the mixed organic solution is not particularly limited, and can be any polyol organic solvent. For example, the organic solvent may be at least one selected from ethylene glycol (EG), diethylene glycol (DEG), glycerin, triethylene glycol (TEG), tetraethylene glycol (TTEG), polyethylene glycol (PEG), dimethyl A group consisting of DMSO and N,N-dimethylformamide (DMF). In an embodiment of the present disclosure, the organic solvent is DEG, glycerin, or a combination thereof.

於本揭露之方法中，以回流方式加熱混合有機溶液至一預定溫度且維持在該預定溫度一預定時間進行反應以獲得磷酸鋰鐵前驅物。於此，預定溫度可介於105^o C至350^o C之間、105^o C至300^o C之間、105^o C至280^o C之間、105^o C至250^o C之間、200^o C至350^o C之間、200^o C至300^o C之間、200^o C至280^o C之間、200^o C至250^o C之間、220^o C至350^o C之間、220^o C至300^o C之間、220^o C至280^o C之間、或220^o C至250^o C之間。於本揭露一實施例中，預定溫度約為220^o C。此外，在預定溫度維持預定時間進行反應以獲得磷酸鋰鐵前驅物。於此，預定時間可介於2小時至20小時之間、2小時至15小時之間、2小時至10小時之間、2小時至8小時之間、2小時至5小時之間、2小時至3小時之間、3小時至20小時之間、3小時至15小時之間、3小時至10小時之間、3小時至8小時之間、或3小時至5小時之間。當進行反應以獲得磷酸鋰鐵前驅物時，溫度可稍微升高。In the method of the present disclosure, the mixed organic solution is heated to a predetermined temperature by reflux and maintained at the predetermined temperature for a predetermined time for reaction to obtain a lithium iron phosphate precursor. Here, the predetermined temperature can be between 105 ^o C to 350 ^o C, 105 ^o C to 300 ^o C, 105 ^o C to 280 ^o C, 105 ^o C to 250 ^o C, 200 ^o Between C to 350 ^o C, 200 ^o C to 300 ^o C, 200 ^o C to 280 ^o C, 200 ^o C to 250 ^o C, 220 ^o C to 350 ^o C, 220 ^o Between C and 300 ^o C, between 220 ^o C and 280 ^o C, or between 220 ^o C and 250 ^o C. In one embodiment of the present disclosure, the predetermined temperature is about 220 ^o C. In addition, the reaction is performed at a predetermined temperature and maintained for a predetermined time to obtain a lithium iron phosphate precursor. Here, the predetermined time can be between 2 hours to 20 hours, 2 hours to 15 hours, 2 hours to 10 hours, 2 hours to 8 hours, 2 hours to 5 hours, 2 hours Between 3 hours and 3 hours, between 3 hours and 20 hours, between 3 hours and 15 hours, between 3 hours and 10 hours, between 3 hours and 8 hours, or between 3 hours and 5 hours. When the reaction is performed to obtain the lithium iron phosphate precursor, the temperature may be slightly increased.

於此，可於一氣氛或一引入氣流下加熱混合有機溶液。該氣氛或該引入氣流可用作一保護氣體或一還原氣體，其可包括一選自由氮氣、氫氣、氦氣、氖氣、氬氣、氪氣、氙氣、一氧化碳、甲烷、氮氫混合氣體、及其混合氣體所組成之群組。於本揭露一實施例中，保護氣體或還原氣體為氮氣、氫氣、或氮氫混合氣體。於本揭露另一實施例中，保護氣體或還原氣體為氮氫混合氣體。Here, the mixed organic solution can be heated under an atmosphere or an introduced air flow. The atmosphere or the introduced gas stream can be used as a protective gas or a reducing gas, which can include a gas selected from the group consisting of nitrogen, hydrogen, helium, neon, argon, krypton, xenon, carbon monoxide, methane, nitrogen and hydrogen, And its mixed gas group. In an embodiment of the present disclosure, the protective gas or the reducing gas is nitrogen, hydrogen, or a mixed gas of nitrogen and hydrogen. In another embodiment of the present disclosure, the protective gas or the reducing gas is a mixed gas of nitrogen and hydrogen.

於本揭露中，加熱混合有機溶液的壓力或進行反應以獲得磷酸鋰鐵前驅物的壓力可約為大氣壓力。然而，傳統形成磷酸鋰鐵粉末的製程通常在高壓力下進行，且進行傳統製程的設備相較於本揭露之方法較為昂貴或複雜。In the present disclosure, the pressure of heating the mixed organic solution or the pressure of the reaction to obtain the lithium iron phosphate precursor may be about atmospheric pressure. However, the traditional process for forming lithium iron phosphate powder is usually performed under high pressure, and the equipment for performing the traditional process is more expensive or complicated than the method disclosed in the present disclosure.

於本揭露之方法中，可於一氣氛或一引入氣流下熱處理磷酸鋰鐵前驅物，以獲得磷酸鋰鐵電極材料。於此，該氣氛或該引入氣流也可用作一保護氣體或一還原氣體，其可包括一選自由氮氣、氫氣、氦氣、氖氣、氬氣、氪氣、氙氣、一氧化碳、甲烷、氮氫混合氣體、及其混合氣體所組成之群組。於本揭露一實施例中，保護氣體或還原氣體為氬氣、氮氣、氫氣、或氮氫混合氣體。於本揭露另一實施例中，保護氣體或還原氣體為氬氣、或氮氫混合氣體。In the method of the present disclosure, the lithium iron phosphate precursor can be heat-treated under an atmosphere or an introduced air flow to obtain the lithium iron phosphate electrode material. Here, the atmosphere or the introduced gas flow can also be used as a protective gas or a reducing gas, which can include a gas selected from nitrogen, hydrogen, helium, neon, argon, krypton, xenon, carbon monoxide, methane, and nitrogen. A group consisting of hydrogen mixed gas and its mixed gas. In an embodiment of the disclosure, the protective gas or the reducing gas is argon, nitrogen, hydrogen, or a mixed gas of nitrogen and hydrogen. In another embodiment of the present disclosure, the protective gas or the reducing gas is argon or a mixed gas of nitrogen and hydrogen.

於本揭露之方法中，熱處理溫度可介於300^o C至1000^o C之間、400^o C至1000^o C之間、500^o C至1000^o C之間、300^o C至900^o C之間、400^o C至900^o C之間、或500^o C至900^o C之間。於本揭露一實施例中，熱處理溫度介於500^o C至860^o C之間。此外，進行熱處理的時間可介於2小時至20小時之間、2小時至15小時之間、2小時至10小時之間、2小時至8小時之間、2小時至5小時之間、或2小時至3小時之間。In the method of the present disclosure, the heat treatment temperature can be between 300 ^o C to 1000 ^o C, 400 ^o C to 1000 ^o C, 500 ^o C to 1000 ^o C, or 300 ^o C to 900 ^o C. Between 400 ^o C and 900 ^o C, or between 500 ^o C and 900 ^o C. In one embodiment of the present disclosure, the heat treatment temperature ranging between 500 ^o C to 860 ^o C. In addition, the heat treatment time can be between 2 hours and 20 hours, between 2 hours and 15 hours, between 2 hours and 10 hours, between 2 hours and 8 hours, between 2 hours and 5 hours, or Between 2 hours and 3 hours.

此外，本揭露獲得的磷酸鋰鐵粉末可用作陰極材料並透過本領域中任何傳統方法以製備一鋰離子電池。在此，概略描述製備鋰離子電池之方法，但本揭露不限於此。In addition, the lithium iron phosphate powder obtained in the present disclosure can be used as a cathode material and can be used to prepare a lithium ion battery by any conventional method in the art. Here, the method of preparing a lithium ion battery is briefly described, but the present disclosure is not limited to this.

於一陽極集電器塗覆一碳材，然後乾燥且壓製碳材以形成用於鋰離子電池的一陽極。於一陰極集電器塗覆一陰極活性材料（即本揭露之磷酸鋰鐵粉末），然後乾燥且壓製陰極活性材料以形成用於鋰離子電池的一陰極。接著，一隔離板***陽極與陰極之間，注入一含鋰電解質，而在包裝後獲得一鋰離子電池。A carbon material is coated on an anode current collector, and then the carbon material is dried and pressed to form an anode for a lithium ion battery. Coating a cathode active material (ie, the lithium iron phosphate powder of the present disclosure) on a cathode current collector, and then drying and pressing the cathode active material to form a cathode for a lithium ion battery. Then, a separator is inserted between the anode and the cathode, and a lithium-containing electrolyte is injected, and a lithium-ion battery is obtained after packaging.

當結合附圖時，從下文詳細描述，本揭露之其他目的、優點、及技術特徵將變得更加清楚。When combined with the drawings, the other objectives, advantages, and technical features of the present disclosure will become clearer from the detailed description below.

當與附圖一起閱讀時，下文實施例清楚地展現本揭露上述和其他技術內容、特徵、及／或效果。When read together with the drawings, the following embodiments clearly demonstrate the above and other technical content, features, and/or effects of the present disclosure.

透過具體實施例的闡述，人們將進一步理解本揭露為達到上文指出的目的所採用的技術手段和效果。另外，由於本文所揭露的內容應為本領域技術人員易於理解且實施的，因此在不遠離本揭露的概念的所有等效置換或修改應由所附的申請專利範圍涵蓋。Through the description of specific embodiments, people will further understand the technical means and effects used by this disclosure to achieve the above-noted objectives. In addition, since the content disclosed herein should be easily understood and implemented by those skilled in the art, all equivalent replacements or modifications without departing from the concept of this disclosure should be covered by the scope of the attached patent application.

再者，當數值介於一第一數值至一第二數值之間時，數值可為該第一數值、該第二數值、或在該第一數值與該第二數值之間的另一數值。Furthermore, when the value is between a first value and a second value, the value can be the first value, the second value, or another value between the first value and the second value .

實施例1至實施例29Example 1 to Example 29

依據下表1合成實施例（於下表1中以Ex縮寫表示）1至實施例29的磷酸鋰鐵前驅物。於下表1中，列出H₃ PO₄ 、FeC₂ O₄ ·2H₂ O、及LiOH·H₂ O之添加量和莫爾比、環境溫度（Temp 1）、相對溼度（RH）、升溫至220^o C的時間（T1）、反應時間（T2）、反應結束之後的最終溫度（Temp 2）、及氮氣氣流（N₂ ）。The lithium iron phosphate precursors of Examples 1 to 29 were synthesized according to Table 1 below (indicated by the abbreviation Ex in Table 1 below). In Table 1 below, _{the addition amount and molar ratio of H 3} PO ₄ , FeC ₂ O ₄ ·2H ₂ O, and LiOH·H ₂ O, ambient temperature (Temp 1), relative humidity (RH), heating Time to 220 ^o C (T1), reaction time (T2), final temperature after the end of the reaction (Temp 2), and nitrogen gas flow (N ₂ ).

於實施例1至實施例25中，H₃ PO₄ （2 g）、FeC₂ O₄ ·2H₂ O（3.6 g）、及LiOH·H₂ O（0.84 g）以比例1:1:1混合，且溶解在二甘醇（100 ml）以獲得混合有機溶液（0.2 M）。於實施例20和實施例26中，十二烷基苯磺酸鈉（0.02 mole）和十二烷基硫酸鈉（0.01 mole）也分別加入混合有機溶液。於實施例27中，以FeC₂ O₄ ·H₂ O:MnC₂ O₄ ·2H₂ O（9:1）取代使用於實施例1中的FeC₂ O₄ ·2H₂ O。於實施例28中，以FeC₂ O₄ ·H₂ O:NiC₂ O₄ ·2H₂ O（9:1）取代使用於實施例1中的FeC₂ O₄ ·2H₂ O。於實施例29中，以FeC₂ O₄ ·H₂ O:MnC₂ O₄ ·2H₂ O:NiC₂ O₄ ·2H₂ O（9:0.5:0.5）取代使用於實施例1中的FeC₂ O₄ ·2H₂ O。接著，加熱混合有機溶液至220^o C。然後，引入氮氣，使混合有機溶液在220^o C和大氣壓力下以回流方式反應一段時間（T2）。反應在大氣壓力下進行。將混合有機溶液過濾之後獲得磷酸鋰鐵前驅物。In Example 1 to Example 25, H ₃ PO ₄ (2 g), FeC ₂ O ₄ ·2H ₂ O (3.6 g), and LiOH·H ₂ O (0.84 g) were mixed in a ratio of 1:1:1 , And dissolved in diethylene glycol (100 ml) to obtain a mixed organic solution (0.2 M). In Example 20 and Example 26, sodium dodecylbenzene sulfonate (0.02 mole) and sodium dodecyl sulfate (0.01 mole) were also added to the mixed organic solution, respectively. In Example 27, FeC ₂ O ₄ ·H ₂ O:MnC ₂ O ₄ ·2H ₂ O (9:1) was used instead of FeC ₂ O ₄ ·2H ₂ O used in Example 1. In Example 28, FeC ₂ O ₄ ·H ₂ O:NiC ₂ O ₄ ·2H ₂ O (9:1) was used instead of FeC ₂ O ₄ ·2H ₂ O used in Example 1. In Example 29, FeC ₂ O ₄ ·H ₂ O:MnC ₂ O ₄ ·2H ₂ O:NiC ₂ O ₄ ·2H ₂ O (9:0.5:0.5) was used in place of FeC _{2 used in Example 1.} O ₄ ·2H ₂ O. Next, heat and mix the organic solution to 220 ^° C. Then, nitrogen is introduced, and the mixed organic solution ^{is reacted in reflux mode at 220 o} C and atmospheric pressure for a period of time (T2). The reaction is carried out under atmospheric pressure. After filtering the mixed organic solution, a lithium iron phosphate precursor is obtained.

獲得的磷酸鋰鐵前驅物由X光繞射儀（島津6000）檢測以獲得其結晶結構。藉由使用銅的Kα輻射以獲得X光繞射圖譜（XRD圖譜），2θ掃描角度介於15^o 至45^o 之間，且掃描速率為1^o /min。圖1為實施例1的磷酸鋰鐵前驅物之XRD圖譜。The obtained lithium iron phosphate precursor was detected by X-ray diffractometer (Shimadzu 6000) to obtain its crystal structure. The X-ray diffraction pattern (XRD pattern) is obtained by using copper Kα radiation. The 2θ scanning angle is between 15 ^° and 45 ^° , and the scanning rate is 1 ^° /min. Figure 1 is the XRD pattern of the lithium iron phosphate precursor of Example 1.

圖1的XRD圖譜具有在接近19.37^o （第2特徵峰）、21.47^o （第4特徵峰）、24.11^o （第6特徵峰）、25.95^o （第7特徵峰）、32.35^o （第10特徵峰）、35^o （第11特徵峰）、36.46^o （第12特徵峰）、及43.83^o （第13特徵峰）的2θ角的特徵峰。此外，圖1的XRD圖譜更具有在接近18.3^o （第1特徵峰）、28.91^o （第8特徵峰）、及30.05^o （第9特徵峰）的2θ角的特徵峰。XRD圖譜不同於具有橄欖石結構的磷酸鋰鐵結晶之XRD圖譜（JCPDS No. 81-1173）。故本揭露之磷酸鋰鐵前驅物不具有橄欖石結構。The XRD pattern of Fig. 1 has the characteristics close to 19.37 ^o (the second characteristic peak), 21.47 ^o (the fourth characteristic peak), 24.11 ^o (the sixth characteristic peak), 25.95 ^o (the seventh characteristic peak), and 32.35 ^o (the tenth characteristic peak). Peak), 35 ^o (the 11th characteristic peak), 36.46 ^o (the 12th characteristic peak), and 43.83 ^o (the 13th characteristic peak). Further, XRD pattern of Figure 1 is more characteristic peaks near 18.3 ^o (first characteristic peaks), 28.91 ^o (8 peaks), and 30.05 ^o (9 characteristic peaks) of 2θ angles. The XRD pattern is different from the XRD pattern of lithium iron phosphate crystals with olivine structure (JCPDS No. 81-1173). Therefore, the lithium iron phosphate precursor disclosed in the present disclosure does not have an olivine structure.

實施例2至實施例29製備的磷酸鋰鐵前驅物也由X光繞射儀檢測，除了在某些實施例的磷酸鋰鐵前驅物之XRD圖譜中的一些特徵峰（特別是第1特徵峰和第8特徵峰）非常微弱或沒有觀察到之外，所得的XRD圖譜相似於圖1所示。下表1中也列出第1特徵峰和第8特徵峰的存在。The lithium iron phosphate precursors prepared in Example 2 to Example 29 were also detected by X-ray diffractometer, except for some characteristic peaks (especially the first characteristic peak) in the XRD patterns of the lithium iron phosphate precursors in some examples. And the 8th characteristic peak) is very weak or not observed, the resulting XRD pattern is similar to that shown in Figure 1. Table 1 below also lists the existence of the first characteristic peak and the eighth characteristic peak.

表1 Ex Temp 1 (ºC) RH (%) T1 T2 Temp 2 (ºC) 氮氣 (c.c./min) 第1特徵峰第8特徵峰 1 29 60 5小時29分 3小時1分 238 100+ V V 2 -- -- 8小時47分 3小時24分 237 100 V V 3 27 68 5小時44分 3小時 239 100+ V V 4 25 70 7小時12分 3小時13分 238 100+ V Δ 5 25 60 2小時57分 3小時1分 242 100+ V V 6 24 50 4小時43分 3小時13分 239 100+ V V 7 29 55 5小時30分 3小時12分 239 100+ V Δ 8 -- -- 4小時22分 3小時 236 100+ V V 9 -- -- 5小時15分 3小時 238 100+ Δ Δ 10 -- -- 6小時29分 3小時2分 236 100+ V Δ 11 -- -- 5小時44分 3小時11分 240 100+ V V 12 23 60 -- -- -- 100+ V Δ 13 23 60 8小時9分 3小時22分 240 100 V V 14 23 60 8小時11分 3小時6分 235 100 V Δ 15 -- -- -- -- 241 100+ Δ Δ 16 25 70 4小時16分 3小時4分 234 100 X V 17 27 55 7小時37分 3小時 235 100 X Δ 18 25 65 8小時43分 3小時 234 100 X X 19 26 55 7小時2分 3小時 234 100 X X 20 23 60 15小時30分 4小時19分 240 100 X Δ 21 25 60 9小時46分 5小時59分 237 100 X X 22 27 70 10小時13分 3小時 235 100+ X X 23 -- -- 5小時25分 5小時34分 242 100+ X X 24 -- -- 4小時15分 16小時23分 243 100+ X X 25 29 65 8小時1分 16小時 241 100 X Δ 26 -- -- -- 3小時 -- 100 V Δ 27 -- -- -- 3小時 -- 100 X X 28 -- -- -- 3小時 -- 100 V V 29 -- -- -- 3小時 -- 100 V+ X V：可發現特徵峰 V+：特徵峰非常強 Δ：特徵峰非常弱或幾乎消失 X：未觀察到特徵峰 --：未檢測Table 1 Ex Temp 1 (ºC) RH (%) T1 T2 Temp 2 (ºC) Nitrogen (cc/min) 1st characteristic peak 8th characteristic peak 1 29 60 5 hours and 29 minutes 3 hours 1 minute 238 100+ V V 2 - - 8 hours 47 minutes 3 hours 24 minutes 237 100 V V 3 27 68 5 hours 44 minutes 3 hours 239 100+ V V 4 25 70 7 hours 12 minutes 3 hours and 13 minutes 238 100+ V Δ 5 25 60 2 hours 57 minutes 3 hours 1 minute 242 100+ V V 6 twenty four 50 4 hours and 43 minutes 3 hours and 13 minutes 239 100+ V V 7 29 55 5 hours 30 minutes 3 hours and 12 minutes 239 100+ V Δ 8 - - 4 hours 22 minutes 3 hours 236 100+ V V 9 - - 5 hours and 15 minutes 3 hours 238 100+ Δ Δ 10 - - 6 hours and 29 minutes 3 hours and 2 minutes 236 100+ V Δ 11 - - 5 hours 44 minutes 3 hours and 11 minutes 240 100+ V V 12 twenty three 60 - - - 100+ V Δ 13 twenty three 60 8 hours and 9 minutes 3 hours 22 minutes 240 100 V V 14 twenty three 60 8 hours and 11 minutes 3 hours and 6 minutes 235 100 V Δ 15 - - - - 241 100+ Δ Δ 16 25 70 4 hours and 16 minutes 3 hours 4 minutes 234 100 X V 17 27 55 7 hours 37 minutes 3 hours 235 100 X Δ 18 25 65 8 hours and 43 minutes 3 hours 234 100 X X 19 26 55 7 hours 2 minutes 3 hours 234 100 X X 20 twenty three 60 15 hours 30 minutes 4 hours and 19 minutes 240 100 X Δ twenty one 25 60 9 hours 46 minutes 5 hours 59 minutes 237 100 X X twenty two 27 70 10 hours and 13 minutes 3 hours 235 100+ X X twenty three - - 5 hours 25 minutes 5 hours 34 minutes 242 100+ X X twenty four - - 4 hours and 15 minutes 16 hours 23 minutes 243 100+ X X 25 29 65 8 hours 1 minute 16 hours 241 100 X Δ 26 - - - 3 hours - 100 V Δ 27 - - - 3 hours - 100 X X 28 - - - 3 hours - 100 V V 29 - - - 3 hours - 100 V+ X V: The characteristic peak can be found V+: The characteristic peak is very strong Δ: The characteristic peak is very weak or almost disappear X: No characteristic peak is observed--: No detection

依據表1中顯示的數據，第1特徵峰和第8特徵峰的存在可能不與環境溫度、相對溼度、升溫至220^o C的時間、反應時間、最終溫度、及氮氣氣流相關。特徵峰的強度（特別是第1特徵峰和第8特徵峰）可能與化合物或在磷酸鋰鐵前驅物中存在化合物的含量相關。According to the data shown in Table 1, the existence of the first characteristic peak and the eighth characteristic peak may not be related to the ambient temperature, relative humidity, heating time to 220 ^o C, reaction time, final temperature, and nitrogen gas flow. The intensity of the characteristic peaks (especially the first characteristic peak and the eighth characteristic peak) may be related to the compound or the content of the compound in the lithium iron phosphate precursor.

依據XRD數據（JCPDS卡），發現含有鋰、鐵、磷、氧、或氫的化合物之XRD圖譜可能具有一個最大強度的特徵峰。於此，藉由將圖1的XRD圖譜與JCPDS卡比較來研究每一特徵峰由何種結晶化合物所貢獻。比較的結果列在下表2中。According to XRD data (JCPDS card), it is found that the XRD pattern of compounds containing lithium, iron, phosphorus, oxygen, or hydrogen may have a characteristic peak with the highest intensity. Here, by comparing the XRD pattern of Fig. 1 with the JCPDS card, we can study which crystalline compound contributes to each characteristic peak. The results of the comparison are listed in Table 2 below.

表2 特徵峰 2θ 化合物1 JCPDS No. 化合物 1之化學式化合物 2 JCPDS No. 化合物2之化學式第1特徵峰 18.3 ° 74-1910 Fe₃ O₄ 磁鐵礦 -- -- 第2特徵峰 19.37 ° 46-1551 C₂ H₄ Li₄ O₇ P₂ ·H₂ O 氫氧化鋰乙基二烯膦酸酯 (Lithium hydroxyl ethyldiene phosphonate) 44-812 Fe₃ H₉ (PO₄ )₆ ·6H₂ O 磷酸氫鐵水合物 (Iron hydrogen phosphate hydrate) 第4特徵峰 21.47 ° 80-2315 Fe₂ Fe(P₂ O₇ )₂ 磷酸鐵(Iron phosphate) -- -- 第6特徵峰 24.11 ° 65-2754 FeLiO₂ 四方氧化鐵(III)鋰 (Tetragonal Lithium iron(III) Oxide) 75-1603 Li₂ Fe₂ O₄ 鐵(III)鋰氧化物 (Lithium iron(III) oxide) 第7特徵峰 25.95 ° 72-2124 FePO₄ 磷酸鐵（III） (Iron(III) phosphate) 33-1721 C₆ H₆ FeO₈ ·2H₂ O 丙二酸氫鐵二水合物 (Iron hydrogen malonate dihydrate) 第8特徵峰 28.91 ° 76-1761 Fe₃ PO₇ 三氧化三鐵（III）磷酸鹽（V） (Triiron(III) trioxide phosphate(V)) 第9特徵峰 30.05 ° 72-2446 Fe₃ Fe₄ (PO₄ )₆ 磷酸鐵(Iron phosphate) 49-1209 C₂ HLiO₄ ·H₂ O 草酸氫鋰水合物 (Lithium hydrogen oxalate hydrate) 第10特徵峰 32.35 ° 72-464 FePO₄ (H₂ O)₂ 磷鐵礦 (Phosphosiderite) 第11特徵峰 35 ° 74-115 Li₂ O₂ 過氧化鋰 (Lithium peroxide) 第12特徵峰 36.46 ° 89-4083 Li 鋰 (Lithim) 第13特徵峰 43.83 ° 48-582 Fe₂ O(PO₄ ) α-氧化鐵磷 (Alpha-iron oxide phosphate) Table 2 Characteristic peak 2θ Compound 1 JCPDS No. Chemical formula of compound 1 Compound 2 JCPDS No. Chemical formula of compound 2 The first characteristic peak 18.3 ° 74-1910 Fe ₃ O ₄ magnetite - - The second characteristic peak 19.37 ° 46-1551 C ₂ H ₄ Li ₄ O ₇ P ₂ ·H ₂ O Lithium hydroxyl ethyldiene phosphonate 44-812 Fe ₃ H ₉ (PO ₄ ) ₆ ·6H ₂ O Iron hydrogen phosphate hydrate 4th characteristic peak 21.47 ° 80-2315 _{_{_{Fe 2 Fe (P 2 O 7}}} ) 2 iron phosphate (Iron phosphate) - - The 6th characteristic peak 24.11 ° 65-2754 FeLiO ₂ Tetragonal Lithium iron(III) Oxide 75-1603 Li ₂ Fe ₂ O ₄ Lithium iron(III) oxide The 7th characteristic peak 25.95 ° 72-2124 FePO ₄ Iron(III) phosphate (Iron(III) phosphate) 33-1721 C ₆ H ₆ FeO ₈ ·2H ₂ O Iron hydrogen malonate dihydrate The 8th characteristic peak 28.91 ° 76-1761 Fe ₃ PO ₇ Triiron(III) trioxide phosphate(V) The 9th characteristic peak 30.05 ° 72-2446 Fe ₃ Fe ₄ (PO ₄ ) ₆ Iron phosphate 49-1209 C ₂ HLiO ₄ ·H ₂ O Lithium hydrogen oxalate hydrate The 10th characteristic peak 32.35 ° 72-464 FePO ₄ (H ₂ O) ₂ Phosphosiderite 11th characteristic peak 35 ° 74-115 Li ₂ O ₂ Lithium peroxide The 12th characteristic peak 36.46 ° 89-4083 Li Lithium (Lithim) The 13th characteristic peak 43.83 ° 48-582 Fe ₂ O(PO ₄ ) Alpha-iron oxide phosphate

此外，實施例1至實施例29獲得的磷酸鋰鐵前驅物也由感應耦合電漿（ICP）檢測。結果顯示在實施例1至實施例29中的磷酸鋰鐵前驅物之鋰、鐵、及磷的原子比非常接近1:1:1（即鋰:鐵:磷=1:1:1），其表示在實施例1至實施例29獲得的磷酸鋰鐵前驅物可直接用於製備磷酸鋰鐵電極材料。In addition, the lithium iron phosphate precursors obtained in Examples 1 to 29 were also detected by inductively coupled plasma (ICP). The results show that the atomic ratio of lithium, iron, and phosphorus in the lithium iron phosphate precursors in Examples 1 to 29 is very close to 1:1:1 (that is, lithium: iron: phosphorus = 1:1:1). It means that the lithium iron phosphate precursor obtained in Example 1 to Example 29 can be directly used to prepare lithium iron phosphate electrode materials.

實施例30至實施例35Example 30 to Example 35

於實施例30至實施例35中，實施例4、實施例6、實施例3、實施例13、實施例9、及實施例14製備的磷酸鋰鐵前驅物透過研磨製程分別塗覆有碳源以在磷酸鋰鐵前驅物之粉末上形成碳層。簡而言之，將碳源溶解在研磨溶液中，接著與磷酸鋰鐵前驅物混合。然後，使用氧化鋯球，進行研磨製程2小時以獲得在其上形成有碳層的磷酸鋰鐵前驅物。於實施例34中，加熱具有碳源（硬脂酸）的研磨溶液以充分溶解硬脂酸。In Examples 30 to 35, the lithium iron phosphate precursors prepared in Example 4, Example 6, Example 3, Example 13, Example 9, and Example 14 were respectively coated with a carbon source through a grinding process To form a carbon layer on the lithium iron phosphate precursor powder. In short, the carbon source is dissolved in the grinding solution and then mixed with the lithium iron phosphate precursor. Then, using zirconia balls, a grinding process was performed for 2 hours to obtain a lithium iron phosphate precursor with a carbon layer formed thereon. In Example 34, the grinding solution with a carbon source (stearic acid) was heated to fully dissolve the stearic acid.

下表3列出了所使用的氧化鋯球之直徑、在研磨製程中使用的研磨溶液、碳源、及碳源對於磷酸鋰鐵前驅物的重量比。此外，所得的塗覆有碳源的磷酸鋰鐵前驅物也由X光繞射儀（島津6000）檢測以獲得其結晶結構。比較具有或不具有碳層的磷酸鋰鐵前驅物之XRD圖譜，而下表3列出比較結果。Table 3 below lists the diameter of the zirconia balls used, the grinding solution used in the grinding process, the carbon source, and the weight ratio of the carbon source to the lithium iron phosphate precursor. In addition, the obtained lithium iron phosphate precursor coated with a carbon source was also detected by an X-ray diffractometer (Shimadzu 6000) to obtain its crystal structure. Compare the XRD patterns of lithium iron phosphate precursors with or without carbon layer, and Table 3 below lists the comparison results.

表3 實施例磷酸鋰鐵前驅物直徑研磨溶液碳源與重量比 XRD圖譜之改變 30 實施例 4 0.8 mm 25 ml 水蔗糖 0.15 第1特徵峰消失第8特徵峰消失第9特徵峰變弱 31 實施例 6 0.8 mm 5 ml 水+ 20 ml 乙醇蔗糖 0.15 第1特徵峰變弱第8特徵峰消失第9特徵峰變弱 32 實施例 3 2 mm 25 ml 水蔗糖 0.15 第1特徵峰變弱第8特徵峰消失第9特徵峰變弱 33 實施例 13 2 mm 5 ml 水+ 20 ml 乙醇蔗糖 0.15 第1特徵峰變弱第8特徵峰消失第9特徵峰變弱 34 實施例 9 2 mm 30 ml 乙醇硬脂酸 0.083 第1特徵峰變弱第8特徵峰消失第9特徵峰變弱 35 實施例 14 2 mm 25 ml 甲苯聚苯乙烯 0.068 第1特徵峰變弱第8特徵峰消失第9特徵峰變弱 table 3 Example Lithium Iron Phosphate Precursor diameter Grinding solution Carbon source to weight ratio Changes in XRD patterns 30 Example 4 0.8 mm 25 ml water Sucrose 0.15 The first characteristic peak disappears, the eighth characteristic peak disappears, and the ninth characteristic peak becomes weaker 31 Example 6 0.8 mm 5 ml water + 20 ml ethanol Sucrose 0.15 The first characteristic peak becomes weak, the eighth characteristic peak disappears, and the ninth characteristic peak becomes weak. 32 Example 3 2 mm 25 ml water Sucrose 0.15 The first characteristic peak becomes weak, the eighth characteristic peak disappears, and the ninth characteristic peak becomes weak. 33 Example 13 2 mm 5 ml water + 20 ml ethanol Sucrose 0.15 The first characteristic peak becomes weak, the eighth characteristic peak disappears, and the ninth characteristic peak becomes weak. 34 Example 9 2 mm 30 ml ethanol Stearic acid 0.083 The first characteristic peak becomes weak, the eighth characteristic peak disappears, and the ninth characteristic peak becomes weak. 35 Example 14 2 mm 25 ml toluene Polystyrene 0.068 The first characteristic peak becomes weak, the eighth characteristic peak disappears, and the ninth characteristic peak becomes weak.

實施例30至實施例35之結果指出，由於研磨製程，磷酸鋰鐵前驅物的結晶減少或在磷酸鋰鐵前驅物的結晶之晶格被破壞。此外，於實施例32至實施例35中，在經研磨製程後，在實施例32中第9特徵峰之強度的降低程度大於實施例33、在實施例33中第9特徵峰之強度的降低程度大於實施例34、而在實施例35中第9特徵峰之強度的降低程度為非常小。這些結果指出第9特徵峰之強度的降低程度與在研磨溶液中之水含量相關。The results of Examples 30 to 35 indicate that due to the grinding process, the crystallization of the lithium iron phosphate precursor is reduced or the crystal lattice of the lithium iron phosphate precursor is destroyed. In addition, in Examples 32 to 35, after the grinding process, the intensity of the ninth characteristic peak in Example 32 is reduced more than in Example 33, and the intensity of the ninth characteristic peak in Example 33 is reduced more than in Example 33. In Example 34, the decrease in the intensity of the ninth characteristic peak in Example 35 was very small. These results indicate that the decrease in the intensity of the ninth characteristic peak is related to the water content in the grinding solution.

實施例1製備的磷酸鋰鐵前驅物之形狀也使用高解析穿透電子顯微鏡（TEM）（捷歐 2010）觀察。圖2A至圖2C為本揭露實施例1的磷酸鋰鐵前驅物一區域之TEM圖。發現80%的磷酸鋰鐵前驅物為非晶區，而20%的磷酸鋰鐵前驅物為結晶區，且結晶區散佈在非晶區中。The shape of the lithium iron phosphate precursor prepared in Example 1 was also observed using a high resolution transmission electron microscope (TEM) (Jieou 2010). 2A to 2C are TEM images of a region of the lithium iron phosphate precursor of Example 1 of the disclosure. It is found that 80% of the lithium iron phosphate precursors are amorphous regions, and 20% of the lithium iron phosphate precursors are crystalline regions, and the crystalline regions are scattered in the amorphous regions.

圖2A的左圖為在放大倍率40,000X下觀察。圖2A的右圖為左圖的圓圈區域，其為磷酸鋰鐵前驅物的一薄片，且為在放大倍率為200,000X下觀察。圖2B為在放大倍率600,000X下觀察的照片，其顯示磷酸鋰鐵前驅物的一薄片是由非晶區和結晶區形成。在由Gatan Microscopy Suite軟體測量後，結果如圖2C所示，圖2C顯示結晶區的d-間距（d-spacing）為2.56埃（Å），其與Li₂ O₂ （JCPDS No. 75-115）的(1, 0, 1)面的晶面間距一致。如圖1和表2所示，磷酸鋰鐵前驅物的最強特徵峰為第11特徵峰，其是由結晶Li₂ O₂ 所貢獻。圖2B和圖2C中所顯示的結晶區具有良好的結晶性，且此結晶區被確定為結晶Li₂ O₂ 。故最強的第11特徵峰應由結晶Li₂ O₂ 貢獻。The left panel of Figure 2A is viewed at a magnification of 40,000X. The right image of FIG. 2A is the circled area of the left image, which is a thin slice of the lithium iron phosphate precursor, and is observed at a magnification of 200,000X. FIG. 2B is a photograph observed at a magnification of 600,000X, which shows that a thin sheet of the lithium iron phosphate precursor is formed by an amorphous region and a crystalline region. After being measured by Gatan Microscopy Suite software, the results are shown in Figure 2C. Figure 2C shows that the d-spacing of the crystalline region is 2.56 Angstroms (Å), which is comparable to Li ₂ O ₂ (JCPDS No. 75-115). ) Has the same interplanar spacing on the (1, 0, 1) plane. As shown in Figure 1 and Table 2, the strongest characteristic peak of the lithium iron phosphate precursor is the 11th characteristic peak, which is contributed _{by crystalline Li 2} O _2. The crystalline region shown in FIGS. 2B and 2C has good crystallinity, and this crystalline region is determined to be crystalline Li ₂ O ₂ . Therefore, the strongest 11th characteristic peak should be contributed _{by crystalline Li 2} O _2.

圖3為本揭露實施例1磷酸鋰鐵前驅物另一區域之TEM圖，其為在放大倍率500,000X下觀察。可在磷酸鋰鐵前驅物的一薄片中發現不同的條紋。如圖3所示，可發現由A、B、及C指出具有不同條紋方向的三個區域，且在由A、B、與C指出的區域之間可能存在一些結晶度不佳的區域。在由Gatan Microscopy Suite軟體測量後，在A區域中，結晶區的d-間距為2.465埃（Å），其與鋰（JCPDS No. 89-4083）的(1, 1, 0)面的晶面間距一致。在B區域中，結晶區的d-間距為2.72埃（Å），其與FePO₄ (H₂ O)₂ （JCPDS No. 72-464）的(1, 2, 2)面的晶面間距相似。在C區域中，結晶區的d-間距為2.06埃（Å），其與Fe₂ O(PO₄ )（JCPDS No. 48-582）的(0, 3, 1)面的晶面間距一致。圖3顯示的結晶區A、B、及C具有良好結晶度，且這些結晶區A、B、及C分別為鋰、結晶FePO₄ (H₂ O)₂ 、及結晶Fe₂ O(PO₄ )；故第12特徵峰、第10特徵峰、及第13特徵峰應分別由鋰、結晶FePO₄ (H₂ O)₂ 、及結晶Fe₂ O(PO₄ )所貢獻。FIG. 3 is a TEM image of another area of the lithium iron phosphate precursor of Example 1 of the disclosure, which is observed at a magnification of 500,000X. Different streaks can be found in a thin sheet of the lithium iron phosphate precursor. As shown in FIG. 3, it can be found that three regions with different fringe directions indicated by A, B, and C, and some regions with poor crystallinity may exist between the regions indicated by A, B, and C. After being measured by Gatan Microscopy Suite software, in the A area, the d-spacing of the crystalline region is 2.465 angstroms (Å), which is the same as the (1, 1, 0) plane of lithium (JCPDS No. 89-4083) The spacing is consistent. In the B area, the d-spacing of the crystalline region is 2.72 angstroms (Å), which is similar to the (1, 2, 2) plane spacing of _{FePO 4} (H ₂ O) _{2 (JCPDS No. 72-464)} . In the C region, the d-spacing of the crystalline region is 2.06 angstroms (Å), which is consistent with the (0, 3, 1) plane spacing of _{Fe 2} O (PO _{4) (JCPDS No. 48-582).} Figure 3 shows that the crystalline regions A, B, and C have good crystallinity, and these crystalline regions A, B, and C are respectively lithium, crystalline FePO ₄ (H ₂ O) ₂ , and crystalline Fe ₂ O (PO ₄ ) ; Therefore, the 12th characteristic peak, the 10th characteristic peak, and the 13th characteristic peak should be contributed by lithium, crystalline FePO ₄ (H ₂ O) ₂ , and crystalline Fe ₂ O (PO ₄ ), respectively.

圖4為本揭露實施例1的磷酸鋰鐵前驅物再一區域之TEM圖，其為在放大倍率600,000X下觀察。可在磷酸鋰鐵前驅物的一薄片中發現不同的條紋。如圖4所示，可發現由D、E、及F指出具有不同條紋方向的三個區域，且在由D、E、與F指出的區域之間可能存在一些結晶度不佳的區域。在由Gatan Microscopy Suite軟體測量後，在D區域中，結晶區的d-間距為2.54埃（Å），其與C₆ H₆ FeO₈ ·2H₂ O（JCPDS No. 33-1721）的(1, 3, 2)面的晶面間距一致。在E區域中，結晶區的d-間距為3.07埃（Å），其與Fe₃ PO₇ （JCPDS No. 76-1761）的(0, 1, 2)面的晶面間距相似。在F區域中，結晶區的d-間距為2.67埃（Å），其與Fe₃ Fe₄ (PO₄ )₆ （JCPDS No. 72-2446）的(2, , 1)面的晶面間距一致。圖4顯示的結晶區D、E、及F具有良好結晶度，且這些結晶區D、E、及F分別為結晶C₆ H₆ FeO₈ ·2H₂ O、結晶Fe₃ PO₇ 、及結晶Fe₃ Fe₄ (PO₄ )₆ ；故第7特徵峰、第8特徵峰、及第9特徵峰應分別由結晶C₆ H₆ FeO₈ ·2H₂ O、結晶Fe₃ PO₇ 、及結晶Fe₃ Fe₄ (PO₄ )₆ 所貢獻。4 is a TEM image of another region of the lithium iron phosphate precursor of Example 1 of the disclosure, which is observed at a magnification of 600,000X. Different streaks can be found in a thin sheet of the lithium iron phosphate precursor. As shown in FIG. 4, it can be found that three regions with different fringe directions are indicated by D, E, and F, and there may be some regions with poor crystallinity between the regions indicated by D, E, and F. After being measured by Gatan Microscopy Suite software, in the D area, the d-spacing of the crystalline region is 2.54 angstroms (Å), which is the same as the (1) of _{C 6} H ₆ FeO ₈ ·2H _{2 O (JCPDS No. 33-1721)} , 3, 2) The interplanar spacing is the same. In the E region, the d-spacing of the crystalline region is 3.07 angstroms (Å), which is similar to the (0, 1, 2) plane spacing of _{Fe 3} PO _{7 (JCPDS No. 76-1761).} In the F region, the d-spacing of the crystalline region is 2.67 Angstroms (Å), which is consistent with the (2,, 1) plane spacing of _{Fe 3} Fe ₄ (PO ₄ ) _{6 (JCPDS No. 72-2446)} . Figure 4 shows that the crystalline regions D, E, and F have good crystallinity, and these crystalline regions D, E, and F are respectively crystalline C ₆ H ₆ FeO ₈ ·2H ₂ O, crystalline Fe ₃ PO ₇ , and crystalline Fe ₃ Fe ₄ (PO ₄ ) ₆ ; Therefore, the seventh characteristic peak, the eighth characteristic peak, and the ninth characteristic peak should be composed of crystalline C ₆ H ₆ FeO ₈ ·2H ₂ O, crystalline Fe ₃ PO ₇ , and crystalline Fe _{3 respectively.} Contributed by Fe ₄ (PO ₄ ) _6.

依據圖2A至圖4顯示的結果，磷酸鋰鐵前驅物為包括非晶區和由不同結晶化合物貢獻結晶區的粉末。故磷酸鋰鐵前驅物粉末由不同的結晶化合物構成。特別是，磷酸鋰鐵前驅物粉末的一薄片可由多於一種結晶化合物構成。According to the results shown in FIGS. 2A to 4, the lithium iron phosphate precursor is a powder including amorphous regions and crystalline regions contributed by different crystalline compounds. Therefore, the lithium iron phosphate precursor powder is composed of different crystalline compounds. In particular, one flake of lithium iron phosphate precursor powder may be composed of more than one crystalline compound.

實施例1製備的磷酸鋰鐵前驅物的形狀也使用掃描式電子顯微鏡（SEM）（日立S-4000）觀察。圖5A至圖5F顯示其結果。The shape of the lithium iron phosphate precursor prepared in Example 1 was also observed using a scanning electron microscope (SEM) (Hitachi S-4000). Figures 5A to 5F show the results.

圖5A為在放大倍率10,000X下觀察。可發現磷酸鋰鐵前驅物為具有薄片的粉末，且粉末的直徑約為5 μm。也可發現粉末具有複數薄片，其聚集形成花朵狀形狀。圖5B為在放大倍率40,000X下觀察。可發現每一個薄片具有約為700 nm至1000 nm的長度。圖5C為在放大倍率150,000X下觀察。可發現每一個薄片具有約為5 nm至14 nm的寬度。Figure 5A shows the observation at a magnification of 10,000X. It can be found that the lithium iron phosphate precursor is a powder with flakes, and the diameter of the powder is about 5 μm. It can also be found that the powder has a plurality of flakes, which are aggregated to form a flower-like shape. Figure 5B shows the observation at a magnification of 40,000X. It can be found that each flake has a length of about 700 nm to 1000 nm. Figure 5C shows the observation at a magnification of 150,000X. It can be found that each flake has a width of about 5 nm to 14 nm.

除了如圖5A至圖5C顯示的形狀之外，磷酸鋰鐵前驅物粉末可具有其他形狀，其中薄片層壓形成頁岩狀形狀。圖5D為在放大倍率10,000X下觀察，其顯示一些薄片聚集形成花朵狀形狀，而一些薄片層壓形成頁岩狀形狀。圖5E為在放大倍率80,000X下觀察。可發現在薄片之間存在間隙以形成頁岩狀形狀。圖5F為在放大倍率150,000X下觀察。可發現每一個薄片具有約為5 nm至10 nm的厚度。故儘管粉末的形狀不同，但磷酸鋰鐵前驅物粉末的薄片具有相似的厚度。In addition to the shapes shown in FIGS. 5A to 5C, the lithium iron phosphate precursor powder may have other shapes, in which flakes are laminated to form a shale-like shape. Figure 5D is an observation at a magnification of 10,000X, which shows that some flakes are gathered to form a flower-like shape, and some flakes are laminated to form a shale-like shape. Figure 5E is viewed at a magnification of 80,000X. It can be found that there are gaps between the flakes to form a shale-like shape. Figure 5F is the observation under the magnification of 150,000X. It can be found that each flake has a thickness of about 5 nm to 10 nm. Therefore, although the shape of the powder is different, the flakes of the lithium iron phosphate precursor powder have a similar thickness.

依據圖5A至圖5G顯示的結果，磷酸鋰鐵前驅物為由薄片構成的粉末。當熱處理本揭露之磷酸鋰鐵前驅物以形成磷酸鋰鐵時，獲得的磷酸鋰鐵粉末也可為由薄片構成的粉末。故鋰離子能以均勻且高密度的方式由粉末中脫嵌，因此鋰離子電池的電流密度可進一步提高。According to the results shown in FIGS. 5A to 5G, the lithium iron phosphate precursor is a powder composed of flakes. When the lithium iron phosphate precursor of the present disclosure is heat-treated to form lithium iron phosphate, the obtained lithium iron phosphate powder may also be a powder composed of flakes. Therefore, lithium ions can be extracted from the powder in a uniform and high-density manner, so the current density of the lithium-ion battery can be further improved.

實施例36至實施例43Example 36 to Example 43

H₃ PO₄ 、FeC₂ O₄ 、及LiOH以比例1:1:1混合，且溶解在二甘醇以獲得混合有機溶液。接著，加熱混合有機溶液至220^o C。然後，引入氮氣，使混合有機溶液在220^o C下以回流方式反應3小時。混合有機溶液過濾之後獲得合成粉末。H ₃ PO ₄ , FeC ₂ O ₄ , and LiOH are mixed in a ratio of 1:1:1, and dissolved in diethylene glycol to obtain a mixed organic solution. Next, heat and mix the organic solution to 220 ^° C. Then, nitrogen gas was introduced, the mixed organic solution was reacted at 220 ^o C in a manner reflux for 3 hours. After filtering the mixed organic solution, a synthetic powder is obtained.

合成粉末以去離子水清洗三次，接著在55^o C下乾燥以獲得磷酸鋰鐵前驅物。The synthetic powder was washed three times with deionized water, and then ^{dried at 55 o} C to obtain a lithium iron phosphate precursor.

將獲得的磷酸鋰鐵前驅物分別與蔗糖（15 wt%）混合，且使用3D混合器將混合物混合2小時以獲得混合粉末。The obtained lithium iron phosphate precursors were respectively mixed with sucrose (15 wt%), and the mixture was mixed for 2 hours using a 3D mixer to obtain mixed powders.

將混合粉末置於引入氮氣的真空熱處理爐、或引入固定氮氣氣流的熱處理爐中，並在750^o C下熱處理2小時。然後，獲得用於電極材料的磷酸鋰鐵粉末。The mixed powder was placed in a vacuum heat treatment furnace introducing nitrogen gas, introduced into a heat treating furnace or in a fixed nitrogen gas flow, and heat treated at 750 ^o C 2 hours. Then, lithium iron phosphate powder for electrode material was obtained.

實施例36至實施例43製備的磷酸鋰鐵前驅物也由X光繞射儀檢測，且獲得的XRD圖譜與圖1所示相似。於此，下文表4中僅列出第1特徵峰和第8特徵峰。The lithium iron phosphate precursor prepared in Example 36 to Example 43 was also detected by an X-ray diffractometer, and the obtained XRD pattern was similar to that shown in FIG. 1. Herein, only the first characteristic peak and the eighth characteristic peak are listed in Table 4 below.

此外，實施例36至實施例43製備的磷酸鋰鐵前驅物和磷酸鋰鐵粉末之形狀也使用掃描式電子顯微鏡（SEM）（日立S-4000）觀察。統整之結果在下表4中。In addition, the shapes of the lithium iron phosphate precursor and lithium iron phosphate powder prepared in Examples 36 to 43 were also observed using a scanning electron microscope (SEM) (Hitachi S-4000). The results of the integration are shown in Table 4 below.

表4 Ex 二甘醇 (ml) 混合有機溶液之濃度磷酸鋰鐵前驅物之XRD特徵磷酸鋰鐵前驅物之形狀磷酸鋰鐵粉末之形狀 36 100 0.22 M 第1特徵峰:小第8特徵峰:小花瓣狀和薄片狀厚度:18~24 nm 花瓣狀之長度:700~1,800 nm 薄片狀之長度:1,500~2,000 nm 花瓣狀和薄片狀厚度:5~25 nm 花瓣狀之長度:550~1,400 nm 薄片狀之長度:700~1,400 nm 37 150 0.22 M 第1特徵峰:中等第8特徵峰:小花瓣狀和薄片狀厚度:15~20 nm 花瓣狀之長度:800~1,800 nm 薄片狀之長度:800~2,400 nm 花瓣狀和薄片狀厚度: 16~20 nm 花瓣狀之長度:450~1,300 nm 薄片狀之長度:800~2,100 nm 38 100 0.33 M 第1特徵峰:中等第8特徵峰:小花瓣狀和薄片狀厚度:20~25 nm 花瓣狀之長度:800~2,000 nm 薄片狀之長度:800~1,900 nm 花瓣狀和薄片狀厚度:12~20 nm 花瓣狀之長度:650~1,400 nm 薄片狀之長度:800~2,000 nm 39 150 0.33 M 第1特徵峰:中等第8特徵峰:小花瓣狀和薄片狀厚度:12~24 nm 花瓣狀之長度:600~1,700 nm 薄片狀之長度:800~1,900 nm 花瓣狀和薄片狀厚度:10~20 nm 花瓣狀之長度:500~1,300 nm 薄片狀之長度:900~2,000 nm 40 100 0.44 M 第1特徵峰:中等第8特徵峰:小花瓣狀和薄片狀厚度:15~20 nm 花瓣狀之長度:450~1,500 nm 薄片狀之長度:450~2,000 nm 花瓣狀和薄片狀厚度:12~24 nm 花瓣狀之長度:350~1,300 nm 薄片狀之長度:500~1,800 nm 41 150 0.44 M 第1特徵峰:中等第8特徵峰:小花瓣狀和薄片狀厚度:16~20 nm 花瓣狀之長度:550~1,550 nm 薄片狀之長度:500~2,600 nm 花瓣狀和薄片狀厚度:12~21 nm 花瓣狀之長度:600~1,500 nm 薄片狀之長度: 600~1,900 nm 42 960 0.48 M 第1特徵峰:非常小第8特徵峰:消失花瓣狀（具有3D結構）和薄片狀厚度:14~23 nm 花瓣狀之長度:600~2000 nm 薄片狀之長度:800~2400 nm 薄片狀之間的間隙: >20 nm 花瓣狀和薄片狀厚度:20 nm 花瓣狀之長度:400~1750 nm 薄片狀之長度:400~2400 nm 43 67 0.66 M 第1特徵峰:大第8特徵峰:小花瓣狀和薄片狀厚度:12~20 nm 花瓣狀之長度:500~1,500 nm 薄片狀之長度:800~1,600 nm 花瓣狀和薄片狀厚度:15~22 nm 花瓣狀之長度:550~1,500 nm 薄片狀之長度:700~1,500 nm Table 4 Ex Diethylene glycol (ml) Concentration of mixed organic solution XRD characteristics of lithium iron phosphate precursor Shape of Lithium Iron Phosphate Precursor Shape of Lithium Iron Phosphate Powder 36 100 0.22 M The first characteristic peak: small The eighth characteristic peak: small The thickness of petals and flakes: 18~24 nm The length of petals: 700~1,800 nm The length of flakes: 1,500~2,000 nm The thickness of petals and flakes: 5~25 nm The length of petals: 550~1,400 nm The length of flakes: 700~1,400 nm 37 150 0.22 M No. 1 characteristic peak: Medium No. 8 characteristic peak: Small The thickness of petals and flakes: 15~20 nm The length of petals: 800~1,800 nm The length of flakes: 800~2,400 nm The thickness of petals and flakes: 16~20 nm The length of petals: 450~1,300 nm The length of flakes: 800~2,100 nm 38 100 0.33 M No. 1 characteristic peak: Medium No. 8 characteristic peak: Small The thickness of petals and flakes: 20~25 nm The length of petals: 800~2,000 nm The length of flakes: 800~1,900 nm The thickness of petals and flakes: 12~20 nm The length of petals: 650~1,400 nm The length of flakes: 800~2,000 nm 39 150 0.33 M No. 1 characteristic peak: Medium No. 8 characteristic peak: Small The thickness of petals and flakes: 12~24 nm The length of petals: 600~1,700 nm The length of flakes: 800~1,900 nm The thickness of petals and flakes: 10~20 nm The length of petals: 500~1,300 nm The length of flakes: 900~2,000 nm 40 100 0.44 M No. 1 characteristic peak: Medium No. 8 characteristic peak: Small The thickness of petals and flakes: 15~20 nm The length of petals: 450~1,500 nm The length of flakes: 450~2,000 nm The thickness of petals and flakes: 12~24 nm The length of petals: 350~1,300 nm The length of flakes: 500~1,800 nm 41 150 0.44 M No. 1 characteristic peak: Medium No. 8 characteristic peak: Small The thickness of petals and flakes: 16~20 nm The length of petals: 550~1,550 nm The length of flakes: 500~2,600 nm The thickness of petals and flakes: 12~21 nm The length of petals: 600~1,500 nm The length of flakes: 600~1,900 nm 42 960 0.48 M No. 1 characteristic peak: very small No. 8 characteristic peak: disappear Petal shape (with 3D structure) and flake-like thickness: 14~23 nm petal-like length: 600~2000 nm flake-like length: 800~2400 nm gap between flakes: >20 nm The thickness of petals and flakes: 20 nm The length of petals: 400~1750 nm The length of flakes: 400~2400 nm 43 67 0.66 M No. 1 characteristic peak: Large No. 8 characteristic peak: Small The thickness of petals and flakes: 12~20 nm The length of petals: 500~1,500 nm The length of flakes: 800~1,600 nm Thickness of petals and flakes: 15~22 nm Length of petals: 550~1,500 nm Length of flakes: 700~1,500 nm

儘管已由較佳實施例對本發明進行說明，但應理解在不悖離於後所述本揭露的精神和範圍的情況下，可做出許多其他可能的修改和變化。Although the present invention has been described with preferred embodiments, it should be understood that many other possible modifications and changes can be made without departing from the spirit and scope of the present disclosure described later.

無no

圖1為本揭露實施例1的磷酸鋰鐵前驅物之XRD圖譜。圖2A至圖2C為本揭露實施例1的磷酸鋰鐵前驅物一區域之TEM圖。圖3為本揭露實施例1的磷酸鋰鐵前驅物另一區域之TEM圖。圖4為本揭露實施例1的磷酸鋰鐵前驅物再一區域之TEM圖。圖5A至圖5F為本揭露實施例1的磷酸鋰鐵前驅物之SEM圖。FIG. 1 is an XRD pattern of the lithium iron phosphate precursor of Example 1 of the disclosure. 2A to 2C are TEM images of a region of the lithium iron phosphate precursor of Example 1 of the disclosure. 3 is a TEM image of another region of the lithium iron phosphate precursor of Example 1 of the disclosure. 4 is a TEM image of another region of the lithium iron phosphate precursor of Example 1 of the disclosure. 5A to 5F are SEM images of the lithium iron phosphate precursor of Example 1 of the disclosure.

Claims

一種製備鋰離子電池電極材料的磷酸鋰鐵前驅物，由下列式(I)表示： LiFe₍ _1-a) M_a PO₄ (I) 其中M包括至少一選自由錳、鉻、鈷、銅、鎳、釩、鉬、鈦、鋅、鋯、鎝、釕、銠、鈀、銀、鎘、鉑、金、鋁、鎵、銦、鈹、鎂、鈣、鍶、硼、及鈮所組成之群組的金屬， 0 ≤ a > 0.5，該磷酸鋰鐵前驅物不具有一橄欖石結構，且該磷酸鋰鐵前驅物係由複數薄片所構成之粉末。A lithium iron phosphate precursor for preparing electrode materials for lithium ion batteries, represented by the following formula (I): LiFe ₍ _1-a) M _a PO ₄ (I) where M includes at least one selected from manganese, chromium, cobalt, copper, The group consisting of nickel, vanadium, molybdenum, titanium, zinc, zirconium, tectonium, ruthenium, rhodium, palladium, silver, cadmium, platinum, gold, aluminum, gallium, indium, beryllium, magnesium, calcium, strontium, boron, and niobium Group of metals, 0 ≤ a> 0.5, the lithium iron phosphate precursor does not have an olivine structure, and the lithium iron phosphate precursor is a powder composed of a plurality of flakes.

如請求項1所述之磷酸鋰鐵前驅物，其中該磷酸鋰鐵前驅物包括一非晶區和一結晶區。The lithium iron phosphate precursor according to claim 1, wherein the lithium iron phosphate precursor includes an amorphous region and a crystalline region.

如請求項2所述之磷酸鋰鐵前驅物，其中該非晶區的含量大於該結晶區的含量。The lithium iron phosphate precursor according to claim 2, wherein the content of the amorphous region is greater than the content of the crystalline region.

如請求項2所述之磷酸鋰鐵前驅物，其中該結晶區包括至少一選自由C₂ H₄ Li₄ O₇ P₂ ·H₂ O、Fe₃ H₉ (PO₄ )₆ ·6H₂ O、Fe₂ Fe(P₂ O₇ )₂ 、FeLiO₂ 、Li₂ Fe₂ O₄ 、FePO₄ 、C₆ H₆ FeO₈ ·2H₂ O、FePO₄ (H₂ O)₂ 、Li₂ O₂ 、Li、及Fe₂ O(PO₄ )所組成之群組。The lithium iron phosphate precursor according to claim 2, wherein the crystallization region includes at least one selected from the group consisting of C ₂ H ₄ Li ₄ O ₇ P ₂ ·H ₂ O, Fe ₃ H ₉ (PO ₄ ) ₆ ·6H ₂ O , Fe ₂ Fe(P ₂ O ₇ ) ₂ , FeLiO ₂ , Li ₂ Fe ₂ O ₄ , FePO ₄ , C ₆ H ₆ FeO ₈ · 2H ₂ O, FePO ₄ (H ₂ O) ₂ , Li ₂ O ₂ , A group consisting of Li, and Fe ₂ O (PO _{4 ).}

如請求項4所述之磷酸鋰鐵前驅物，其中該結晶區更包括至少一選自由Fe₃ O₄ 、Fe₃ PO₇ 、Fe₃ Fe₄ (PO₄ )₆ 、及C₂ HLiO₄ ·H₂ O所組成之群組。The lithium iron phosphate precursor according to claim 4, wherein the crystalline region further includes at least one selected from Fe ₃ O ₄ , Fe ₃ PO ₇ , Fe ₃ Fe ₄ (PO ₄ ) ₆ , and C ₂ HLiO ₄ ·H ₂ O group consisting of.

如請求項1所述之磷酸鋰鐵前驅物，其X光繞射圖譜具有在接近19.37^o 、21.47^o 、24.11^o 、25.95^o 、32.35^o 、35^o 、36.46^o 、及43.83^o 的2θ角的特徵峰。The lithium iron phosphate precursor as described in claim 1, its X-ray diffraction pattern has 2θ angles ^{close to 19.37 o} , 21.47 ^o , 24.11 ^o , 25.95 ^o , 32.35 ^o , 35 ^o , 36.46 ^o , and 43.83 ^o Characteristic peaks.

如請求項6所述之磷酸鋰鐵前驅物，其X光繞射圖譜更具有在接近18.3^o 、28.91^o 、及30.05^o 的2θ角的特徵峰。The requested item 6 of the lithium iron phosphate precursor, X-ray diffraction pattern which is more closer to 18.3 ^{^o,} 28.91 ^o, and 30.05 ^o characteristic peaks at 2θ angles.

如請求項1所述之磷酸鋰鐵前驅物，其中該粉末的直徑介於800 nm至5 μm之間，每一該複數薄片的長度分別介於400 nm至5000 nm之間，而每一該複數薄片的厚度分別介於1 nm至50 nm之間。The lithium iron phosphate precursor according to claim 1, wherein the diameter of the powder is between 800 nm and 5 μm, the length of each of the plurality of flakes is between 400 nm and 5000 nm, and each The thickness of the plurality of flakes is between 1 nm and 50 nm, respectively.

如請求項8所述之磷酸鋰鐵前驅物，其中該複數薄片聚集形成一花朵狀形狀或層壓形成一頁岩狀形狀。The lithium iron phosphate precursor according to claim 8, wherein the plurality of flakes are gathered to form a flower-like shape or laminated to form a shale-like shape.

如請求項1所述之磷酸鋰鐵前驅物，其中該粉末更塗覆有一碳層。The lithium iron phosphate precursor according to claim 1, wherein the powder is further coated with a carbon layer.

一種製備鋰離子電池電極材料的磷酸鋰鐵前驅物之製備方法，包括以下步驟：提供一混合有機溶液，其包括鋰、鐵、及磷，其中該混合有機溶液中所含的鋰係源自一含鋰前驅物或一含磷和含鋰前驅物，該混合有機溶液中所含的鐵係源自一含鐵前驅物或一含磷和含鐵前驅物，而該混合有機溶液中所含的磷係源自一含磷前驅物、一含磷和含鋰前驅物、或一含磷和含鐵前驅物；以及以回流方式加熱該混合有機溶液至一預定溫度且維持在該預定溫度一預定時間，以獲得一磷酸鋰鐵前驅物，其中該磷酸鋰鐵前驅物由下列式(I)表示： LiFe₍ _1-a) M_a PO₄ (I) 其中M包括至少一選自由錳、鉻、鈷、銅、鎳、釩、鉬、鈦、鋅、鋯、鎝、釕、銠、鈀、銀、鎘、鉑、金、鋁、鎵、銦、鈹、鎂、鈣、鍶、硼、及鈮所組成之群組的金屬，0 ≤ a > 0.5，該磷酸鋰鐵前驅物不具有一橄欖石結構，且該磷酸鋰鐵前驅物係由複數薄片所構成之粉末。A method for preparing a lithium iron phosphate precursor for preparing a lithium ion battery electrode material includes the following steps: providing a mixed organic solution, which includes lithium, iron, and phosphorus, wherein the lithium contained in the mixed organic solution is derived from a Lithium-containing precursor or a phosphorus-containing and lithium-containing precursor, the iron contained in the mixed organic solution is derived from an iron-containing precursor or a phosphorus-containing and iron-containing precursor, and the mixed organic solution contains Phosphorus is derived from a phosphorus-containing precursor, a phosphorus-containing and lithium-containing precursor, or a phosphorus-containing and iron-containing precursor; and the mixed organic solution is heated by reflux to a predetermined temperature and maintained at the predetermined temperature. Time to obtain a lithium iron phosphate precursor, wherein the lithium iron phosphate precursor is represented by the following formula (I): LiFe ₍ _1-a) M _a PO ₄ (I) where M includes at least one selected from manganese, chromium, Cobalt, copper, nickel, vanadium, molybdenum, titanium, zinc, zirconium, tectonium, ruthenium, rhodium, palladium, silver, cadmium, platinum, gold, aluminum, gallium, indium, beryllium, magnesium, calcium, strontium, boron, and niobium The metal of the group consisting of 0 ≤ a> 0.5, the lithium iron phosphate precursor does not have an olivine structure, and the lithium iron phosphate precursor is a powder composed of a plurality of flakes.

如請求項11所述之製備方法，更包括透過一研磨製程以在該磷酸鋰鐵前驅物上塗覆一碳源以在該粉末上形成一碳層的步驟。The preparation method according to claim 11, further comprising a step of coating a carbon source on the lithium iron phosphate precursor through a grinding process to form a carbon layer on the powder.

如請求項11所述之製備方法，其中於一氣氛或一引入氣流下加熱該混合有機溶液。The preparation method according to claim 11, wherein the mixed organic solution is heated in an atmosphere or an introduced air flow.

如請求項13所述之製備方法，其中該氣氛或該引入氣流包括一選自由氮氣、氦氣、氖氣、氬氣、氪氣、氙氣、一氧化碳、甲烷、氮氫混合氣體、及其混合氣體所組成之群組。The preparation method according to claim 13, wherein the atmosphere or the introduced gas flow includes a gas selected from the group consisting of nitrogen, helium, neon, argon, krypton, xenon, carbon monoxide, methane, a mixed gas of nitrogen and hydrogen, and a mixed gas thereof The group formed by.

如請求項11所述之製備方法，其中該含鋰前驅物為至少一選自由LiOH、Li₂ CO₃ 、LiNO₃ 、CH₃ COOLi、Li₂ C₂ O₄ 、Li₂ SO₄ 、LiCl、LiBr、及LiI所組成之群組；該含鐵前驅物為至少一選自由FeCl₂ 、FeBr₂ 、FeI₂ 、FeSO₄ 、(NH₄ )₂ Fe(SO₄ )₂ 、Fe(NO₃ )₂ 、FeC₂ O₄ 、(CH₃ COO)₂ Fe、及FeCO₃ 所組成之群組；該含磷前驅物為至少一選自由H₃ PO₄ 、NaH₂ PO₄ 、Na₂ HPO₄ 、Mg₃ (PO₄ )₂ 、及NH₄ H₂ PO₄ 所組成之群組；該含磷和含鋰前驅物為至少一選自由LiH₂ PO₄ 、Li₂ HPO₄ 、及Li₃ PO₄ 所組成之群組；而該含磷和含鐵前驅物為至少一選自由Fe₃ (PO₄ )₂ 、及FePO₄ 所組成之群組。The preparation method according to claim 11, wherein the lithium-containing precursor is at least one selected from LiOH, Li ₂ CO ₃ , LiNO ₃ , CH ₃ COOLi, Li ₂ C ₂ O ₄ , Li ₂ SO ₄ , LiCl, LiBr , And LiI; the iron-containing precursor is at least one selected from FeCl ₂ , FeBr ₂ , FeI ₂ , FeSO ₄ , (NH ₄ ) ₂ Fe(SO ₄ ) ₂ , Fe(NO ₃ ) ₂ , FeC ₂ O ₄ , (CH ₃ COO) ₂ Fe, and FeCO ₃ ; the phosphorus-containing precursor is at least one selected from H ₃ PO ₄ , NaH ₂ PO ₄ , Na ₂ HPO ₄ , Mg ₃ ( PO ₄ ) ₂ , and NH ₄ H ₂ PO ₄ ; the phosphorus-containing and lithium-containing precursor is at least one selected from the group consisting of LiH ₂ PO ₄ , Li ₂ HPO ₄ , and Li ₃ PO ₄ And the phosphorus-containing and iron-containing precursors are at least one selected from the group consisting of _{Fe 3} (PO ₄ ) ₂ and FePO _4.

如請求項11所述之製備方法，其中於大氣壓力下加熱該混合有機溶液。The preparation method according to claim 11, wherein the mixed organic solution is heated under atmospheric pressure.

如請求項11所述之製備方法，其中在該混合有機溶液中的一有機溶劑為至少一選自由乙二醇(EG)、二甘醇(DEG)、甘油、三甘醇(TEG)、四甘醇(TTEG)、聚乙二醇(PEG)、二甲基亞碸(DMSO)、及N,N-二甲基甲醯胺(DMF)所組成之群組。The preparation method according to claim 11, wherein an organic solvent in the mixed organic solution is at least one selected from ethylene glycol (EG), diethylene glycol (DEG), glycerol, triethylene glycol (TEG), four Glycol (TTEG), polyethylene glycol (PEG), dimethyl sulfide (DMSO), and N,N-dimethylformamide (DMF).

如請求項11所述之製備方法，其中該預定溫度介於105^o C至350^o C之間，而該預定時間介於2小時至20小時之間。The production method of item 11, wherein the request, wherein the predetermined temperature is between 105 ^o C to 350 ^o C, while the predetermined time is between 2 hours to 20 hours.

如請求項11所述之製備方法，其中該磷酸鋰鐵前驅物的X光繞射圖譜具有在接近19.37^o 、21.47^o 、24.11^o 、25.95^o 、32.35^o 、35^o 、36.46^o 、及43.83^o 的2θ角的特徵峰。The preparation method according to claim 11, wherein the X-ray diffraction pattern of the lithium iron phosphate precursor has approximately 19.37 ^o , 21.47 ^o , 24.11 ^o , 25.95 ^o , 32.35 ^o , 35 ^o , 36.46 ^o , and 43.83 ^o The characteristic peak of the 2θ angle.

如請求項19所述之製備方法，其中該磷酸鋰鐵前驅物的X光繞射圖譜更具有在接近18.3^o 、28.91^o 、及30.05^o 的2θ角的特徵峰。The preparation method of claim 19 request, wherein the X-ray diffraction of the lithium iron phosphate precursor more pattern with characteristic peaks near 18.3 ^{^o,} 28.91 ^o, and angles 2θ of 30.05 ^o.

如請求項11所述之製備方法，其中該混合有機溶液更包括一分散劑。The preparation method according to claim 11, wherein the mixed organic solution further includes a dispersant.

如請求項21所述之製備方法，其中該分散劑為至少一選自由十二烷基硫酸鉀、十二烷基硫酸銨、十二烷基硫酸鈣、十二烷基硫酸鈉、十二烷基硫酸銅、十二烷基硫酸鈉、十四烷基硫酸鈉、十六烷基硫酸鈉、十二烷基苯磺酸鈉、十二烷基苯磺酸鎂、十二烷基磺酸鈉、十二烷基磺酸鎂、癸基磺酸鈉、及癸基硫酸鈉所組成之群組。The preparation method according to claim 21, wherein the dispersant is at least one selected from potassium lauryl sulfate, ammonium lauryl sulfate, calcium lauryl sulfate, sodium lauryl sulfate, dodecane Copper base sulfate, sodium lauryl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium dodecylbenzene sulfonate, magnesium dodecylbenzene sulfonate, sodium dodecyl sulfonate , Magnesium dodecyl sulfonate, sodium decyl sulfonate, and sodium decyl sulfate.