201240197 六、發明說明： 【發明所屬之技術領域】 本發明係關於-種石墨微粉應用於鐘離子電池負 料及其製備方法，尤指-種採負極材料廠生產時所產 料的天然石墨微粉，將該天然石墨微粉與高分子樹脂搜摔 混合後，翻用乾財式餘，趣射_理而 -石墨複合材，製作成-轉子電池負極材料。 【先前技術】 經離子二次電池的負極㈣在最近幾年被廣泛的研究， 因為傳統上以鋰金屬做為鋰電池負極材料存在著許多缺點， 其中包括齡屬表面產生樹枝狀結晶物析出，除了有安全上 的問題外’綱壽命也受辟。這些因素騎使f池失效。 而現今最被廣泛應㈣莫過於碳系統，目前商#化_ =池所使用之負極材料為石墨，其中石墨又可分為人工石 ”然石墨。而人工石墨中的介穩相球狀碳(MCMB)，繁 在 需㈣石墨化爐處理’造成生產成本過高的問題。 覆瀝青方面雖然有較小的比表面積，有較低的 性，L’並可以改善石墨負極材與電解液的相容 產成本Μ絲，但战著纽電 立 =容量會持續魏，造賴環壽命變f 售 =石，料其粉體平均粒徑為 :石因為負極材料時其粒徑過小，性能較差難 美於先千=成奸多廢料的產生與生產成本過高等問題。 土、月，J青專利（申請公佈第CN刪議4八號） 201240197 才木用天然鱗片石墨微粉與黏結劑如聚乙烯醇(pVA)、羧甲基纖 維素(CMC)、聚乙烯賴·^(ρνΒ)混合，經傭乾燥後，再 經600〜1000€碳化熱處理，其研究發現碳化後可得到20〜50 μηι的球形石墨粉體，電容量測試後有較高的比容量與好的充 放電循環性能，但上述方法發現首次庫倫效率為8〇〜88%，其 首次庫偷效率偏低’加上其為低含碳量之黏結劑經碳化處 理’其碳化生產過程巾低分子量散失造成空氣污染需加以處 理，導致生產成本較高等缺點。 曰本專利特開第2002-117851號則是採用聚烯丙基胺水溶 液與石墨粉混合，加熱到12〇1 一邊攪拌一邊加熱到水攪乾 後，將粉末真空乾燥烘乾，得其粉末可做為鋰離子電池負極 材料，然而此固態攪拌乾燥法應用於大量生產時，由於水分 乾燥裡外不均，容易造成石墨粉顆粒互相黏貼聚集，不利於 粒徑包覆與分散，於電極塗佈過程產生不均的現像。故為提 昇放電電容量、降低不可逆容量、改善顆粒成型分散並降低 生產成本，疋以提出本發明。 【發明内容】 有鑒於習用已採用之多型態碳材料作為鋰離子二次電 池負極材料’除了碳材經石墨化後高成本且繁瑣的製程， 與全球對於3C電子產品、電動手工具、電動車的需求大 幅成長’因此，發明人依據多年來從事此課題之相關經 驗’經過長久努力研究與實驗，並配合相關學理，開發設 計出本發明之一種「石墨微粉應用於鋰離子電池負極材料 及其製備方法」。 201240197 本發明之目的即在提供一種以天然石墨為基礎之鋰離 子電池負極材料，係先將石墨與高分子樹脂（酚醛樹脂、 聚丙浠腈(PAN)、聚笨胺(PA)、聚丙稀酿胺(paa)、聚乙稀 醇（PVA)、聚苯乙烯磺酸鈉(PSS)、聚3,4_乙烯二氧噻吩 (PEDOT))攪拌混合，為由粒徑約為卜⑺μίη的球形石墨細 粉，與尚分子樹脂混合成漿體，再由噴霧乾燥機製作成 15〜25 μπι顆粒狀粉體後，即獲得表面改質碳材之石墨複合 碳材。 本發明之次一目的為提供該鐘離子電池負極材料之製 備方法。 為達成上述本發明目的之技術手段在於：以成份為球 形1〜10 μηι天然石墨作為鋰離子電池負極材料之碳材，該 負極材配方法包括：利用卜⑺阿的球形石墨微粉與高 分子樹脂混合，、時均勻混合成泥錄；在經由 喷霧乾燥機造粒與絲過財製造出㈣，其喷霧乾燥進 口溫度為200〜38〇t，出口溫度為兀〜贼，乾燥後即得到 粒徑為15〜25㈣的球形複合石墨粉，其複合石墨粉為石墨 表面披覆糾之球形粉體，以作為鐘離子電池負極材料。 【實施方式】 為f☆胃審查委員崎本發明之技術手段及運作過程 有更進-步之認識與瞭解，_實施麻合圖式，詳細說明 201240197 材，先將石墨與高分子樹脂攪拌混合，為粒徑約為1〜沁 μιη的球形石墨細粉，與高分子樹脂混合成漿體，再由噴= 乾燥機製作成15〜25 μιη顆粒狀粉體後，即獲得表面改山 材之石墨複合碳材。 碳 請參閱第2圖所示，係為本發明前述石墨碳材之 流程圖，該石墨碳材之製備方法包括下列步驟： 首先執行步驟SH)，將粒徑W0帅天然石墨微於與 0=0 wt%比例之高分子樹脂（如：高分子導電樹^高 分子化合物）混合並加入適當比例的溶劑，例如：水门 加水溶性樹脂）或甲醇、乙醇（添加醇溶性樹脂）之後= 授拌，麟1〜10小時形成襞狀液體，如是採醇溶性樹脂則 須先將醇類溶劑去除，利㈣拌加熱的方式；加執溫产 70〜_下將_溶劑去除後’再投人噴霧乾燥機内 著進至步驟S11。 於步驟S11中，將聚料投入喷霧乾燥機内，利用喷霧 乾燥機乾燥造粒之效能製錢丨5〜25 粉體，喷霧 乾燥機其原理為將;5錢_化後_麟，使霧滴收縮 升> 成類球狀乾燥粉體，接著進至步驟8丨2。 於步驟S12中，其噴霧乾燥機溫度參數設定:進口溫度 為200〜38GC ’出口溫度為冗〜⑼。^，經喷霧乾燥後即得到 本發明之石墨複合碳材，並將其作為鋰離子電池負極 料。 、 凊參閱第3圖所示，係為石墨複合碳材50次放電循環 次數電容量圖。201240197 VI. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a graphite powder micropowder for use in a clock ion battery negative material and a preparation method thereof, and more particularly to a natural graphite powder produced by the production of a negative electrode material factory. The natural graphite micropowder is mixed with the polymer resin, and then the dry material is used, and the funky-graphite composite material is fabricated into a negative electrode material for the rotor battery. [Prior Art] The negative electrode (IV) of an ion secondary battery has been extensively studied in recent years because conventionally, lithium metal is used as a negative electrode material for a lithium battery, and there are many disadvantages, including precipitation of dendritic crystals on the surface of the genus, In addition to the safety issues, the life of the program is also exploited. These factors cause the f pool to fail. Nowadays, the most widely used (four) is the carbon system. At present, the negative electrode material used in the pool is graphite, and the graphite can be divided into artificial stone and graphite. The metastable phase spherical carbon in artificial graphite (MCMB), the need for (four) graphitization furnace treatment 'causes the production cost is too high. Although the asphalt surface has a smaller specific surface area, has lower properties, L' can improve the graphite anode material and electrolyte Compatible production cost Μ silk, but the battle with New Electric 立 = capacity will continue Wei, the life of the aging ring becomes f = stone, the average particle size of the powder is: stone because of the negative material, its particle size is too small, poor performance It is difficult to be beautiful in the first thousand = the production of multiple wastes and the high production costs. Earth, month, J Qing patent (application for publication CN deletes No. 4 8) 201240197 Cai wood with natural flake graphite powder and binder such as poly Vinyl alcohol (pVA), carboxymethyl cellulose (CMC), polyethylene Lai ^ (ρνΒ) mixed, after drying, and then carbonized heat treatment of 600~1000€, the research found that carbonization can get 20~50 μηι Spherical graphite powder with a higher ratio after capacitance test The amount and the good charge and discharge cycle performance, but the above method found that the first coulombic efficiency is 8〇~88%, its first low stealing efficiency 'plus its low carbon content binder through carbonization' its carbonization production process The low molecular weight loss of the towel causes air pollution to be treated, resulting in high production cost, etc. 曰 Patent No. 2002-117851 is a mixture of polyallylamine aqueous solution and graphite powder, heated to 12〇1 while stirring. After heating to water, the powder is dried by vacuum drying, and the powder can be used as a negative electrode material for lithium ion batteries. However, when the solid state stirring and drying method is applied to mass production, the graphite powder is easily formed due to uneven moisture inside and outside. The particles adhere to each other and aggregate, which is not conducive to particle size coating and dispersion, and produces uneven images during electrode coating process. Therefore, in order to increase discharge capacity, reduce irreversible capacity, improve particle formation dispersion, and reduce production cost, the present invention is proposed. [Disclosed] In view of the conventional use of polymorphic carbon materials as anode materials for lithium ion secondary batteries, except for carbon materials The high cost and cumbersome process after inking, and the global demand for 3C electronic products, electric hand tools, and electric vehicles have grown greatly. Therefore, the inventors have long been working hard on research and experiments based on years of experience in this subject. In accordance with the relevant theory, a "graphite micropowder is applied to a lithium ion battery anode material and a preparation method thereof" according to the present invention. 201240197 The object of the present invention is to provide a lithium ion battery anode material based on natural graphite, which is firstly made of graphite and polymer resin (phenolic resin, polyacrylonitrile (PAN), polystyrene (PA), polypropylene. Amine (paa), polyvinyl alcohol (PVA), sodium polystyrene sulfonate (PSS), poly 3,4-ethylene dioxythiophene (PEDOT) are stirred and mixed to form spherical graphite with a particle size of about (7) μίη. The fine powder is mixed with the molecular resin to form a slurry, and then formed into a 15~25 μπι granular powder by a spray dryer to obtain a graphite composite carbon material having a surface modified carbon material. A second object of the present invention is to provide a method of preparing the anode material of the ion battery. The technical means for achieving the above object of the present invention is as follows: a natural graphite having a spherical composition of 1 to 10 μηι is used as a carbon material for a negative electrode material of a lithium ion battery, and the method for dispensing the negative electrode material comprises: using spherical graphite powder and polymer resin of Bu (7) Mixing, and evenly mixing into a mud record; making granulation and silk through the spray dryer to produce (4), the spray drying inlet temperature is 200~38〇t, the outlet temperature is 兀~thief, after drying, it is obtained The spherical composite graphite powder having a particle diameter of 15 to 25 (four), the composite graphite powder is a spherical powder coated with a surface of the graphite, and is used as a negative electrode material for a clock ion battery. [Embodiment] For the f ☆ stomach review committee, the technical means and operation process of the invention have a further step-by-step understanding and understanding, _ implementation of the hemp pattern, detailing the 201240197 material, first mixing the graphite with the polymer resin , a spherical graphite fine powder having a particle diameter of about 1 to 沁μιη, mixed with a polymer resin to form a slurry, and then formed into a 15~25 μηη granular powder by a spray=dryer, thereby obtaining a graphite of a surface-modified mountain material. Composite carbon material. Carbon is shown in Figure 2, which is a flow chart of the graphite carbon material of the present invention. The method for preparing the graphite carbon material comprises the following steps: First, step SH) is performed to make the particle size W0 handsome natural graphite slightly and 0= 0 wt% of polymer resin (such as: polymer conductive tree ^ polymer compound) mixed with appropriate proportion of solvent, such as: water gate plus water-soluble resin) or methanol, ethanol (add alcohol-soluble resin) = mix, Lin 1~10 hours to form a sputum liquid, if the alcohol-soluble resin is used, the alcohol solvent must be removed first, and the heating method is used for heating (4); the temperature is 70~_, the solvent is removed, and then the spray is dried. The machine proceeds to step S11. In step S11, the material is put into a spray dryer, and the granulation efficiency of the granulation is performed by a spray dryer to make a powder of 5 to 25 powder. The principle of the spray dryer is 5; The droplets are allowed to shrink and grow into a spherical dry powder, and then proceed to step 8丨2. In step S12, the spray dryer temperature parameter is set: the inlet temperature is 200 to 38 GC 'the outlet temperature is redundant ~ (9). ^, the graphite composite carbon material of the present invention is obtained by spray drying, and is used as a negative electrode material for a lithium ion battery.凊 Refer to Figure 3 for the capacitance of 50 times of the cycle of graphite composite carbon.
S 6 201240197 下列為比較例與實施例的描述，以說明本發明之特點 與優勢，首先針對比較例1敘述，然後再對實施例】至實施 例4加以比較’來證明本發明之效果。 比較例1 :將平均粒徑3 μιη天然石墨微粉與酒精混合 加入反絮凝劑’調節固含量至30〜50 wt%，再加入石墨二 粉質量5%的聚乙烯醇缩丁醛(pVB)作為黏結劑，再攪拌槽 中攪拌2〜5小時後，再採喷霧乾燥機進行乾燥、造粒，並 經由碳化爐做熱處理，其中熱處理溫度600〜1〇〇〇<t，所得 粉體作為裡離子負極材，而塗佈與電池組裝之方法如下. 將0_1 wt%微量草酸與1〇 wt〇/0之聚偏氟乙烯(pvDF)黏結 劑(Binder)混入N—曱基呲咯烷酮(NMP)溶劑中，均勻攪 拌20分鐘，使得該聚偏氟乙烯能均勻分散於該溶劑之混 合液中；將該石墨碳粉末置入攪拌均勻之該混合液，持續 攪拌20分鐘後該混合液形成泥漿狀物，以13〇 μιη刮刀均 勻塗佈在一銅箔上，以10(rC烘乾去除殘留溶劑，以25% 之碾壓率進行碾壓，再以n(rc烘乾。電池組裝部份先把 塗佈元整之負極極片裁成直徑13 cm的圓板，正極則採用 鋰金屬箔片；硬幣形電池所需之組件，於乾燥氣氛控制室 中依序組裝，並添加電解質液（1M鐘六氟碟酸鹽 (LiPF6 )(溶質）_碳酸乙烯酯（EC ) /碳酸曱乙醋 (EMC)(溶劑）（Volume 1:2))，即完成一硬幣形電 池；組裝完成之硬幣型電池進行連續充放電性能測試，其 充放電速率為0.2C定電流密度進行連續充放電5〇次，充 電戴止電壓為2V (vs· Li / U+ )，放電戴止電壓為〇 〇〇5v 201240197 (vs. Li / Li )。其首次充電電容量為400.8 mAh/g，放電 電容量為341.8 mAh/g ’庫倫效率為85.2%。第50次充電 電容量為340.6 mAh/g ’放電電容量為322.8 mAh/g。 實施例1 :將平均粒徑3 μπι的天然石墨3〇g與〇.9g的樹 脂聚丙烯醯胺(PAA)加入去離子水中混合攪拌，攪拌時間 為1〜5小時，混合成漿體後再採喷霧乾燥機進行乾燥、造 粒’其喷霧乾燥進口溫度為28〇。(：，出口溫度為15(TC，乾燥 後可得到粒徑約為15〜25 μιη的複合石墨粉，可作為負極材料 使用。其電池之備製方式與電容量測試同比較例丨。此材料 首次充電電容量為399.6 mAh/g，放電電容量為36〇 mAh/g，庫倫效率為90。/。。第50次充電電容量為364 6 mAh/g ’放電電容量為358.5 mAh/g。比較上述實驗，可 知實施例1之放電電容量及庫倫效率以及循環穩定性明顯 較比較例1來得佳。 實施例2 :將粒徑1 μιη的天然石墨微粉3〇g與〇.6g之聚 3, 4-乙烯二氧噻吩(PED〇T)樹脂加入足量的去離子水中混 口授拌，攪拌時間為1〜5小時，混合成漿體後再採喷霧乾燥 機進行乾燥、造粒，其喷霧乾燥進口溫度為28(^c，出口溫 度為150 C乾燦後可得到粒徑約為1 $〜25 μηι的複合石墨 粉，可作為負極材料使用，其電池之備製方式與電容量測試 同比較例1。此材料首次充電電容量為379.1 mAh/g，放電 電容量為348.8 mAh/g，庫倫效率為92%。第50次充電電 容量為350.6 mAh/g，放電電容量為346.8 mAh/g，循環 性與放電電容量亦較比較例1有明顯提升且穩定。 201240197 實施例3 :將粒徑2μιη的天然石墨30g與3g水性酚醛樹 脂，加入去離子水混合擾拌，授拌時間為1〜5小時，混合 成漿體後再採喷霧乾燥機進行乾燥、造粒，其喷霧乾燥進 口溫度為28(TC，出口溫度為150°C，乾燥後可得到粒徑約為 15〜25 μπι的複合石墨粉，然後再經1250。(：碳化熱處理後，可 作為負極材料使用，其電池之備製方式與電容量測試同比較 例1。此材料首次充電電容量為388.4mAh/g，放電電容量 為348.7mAh/g，庫倫效率為89.8%。第50次充電電容量 為355.8mAh/g ’放電電容量為346.2mAh/g，亦較比較例 1之電容量大且穩定。 實施例4 :將15 μπι的天然石墨3〇g與〇.6g聚3,4-乙烯二 氧噻吩(PEDOT)樹脂加入去離子水中混合攪拌，攪拌時間 為1〜5小時，混合成漿體後再採喷霧乾燥機進行乾燥，其喷 霧乾燥進口溫度為280t，出口溫度為15〇。(：乾燥後可得到粒 從約為18〜20 μιη的複合石墨粉，可作為負極材料使用，其電 池之備製方式與電容量測試同比較例丨。此材料首次充電電 各量為377.2 mAh/g，放電電容量為3415 mAh/g ,庫倫 欵率為90.5%。第50次充電電容量為360 5 mAh/g，放電 電各量為339.1 mAh/g。 综合上述實驗可以了解在包覆相同且等量的高分子樹 月9下，當採用粒徑15〜18 μιη的天然石墨包覆高分子樹脂之 電各量與庫倫效率等性質，與採用細粒徑1〜10 μιη天然石墨 微粉包覆高分子樹脂性質是相當接近，因此可以進一步確 又，細小粒徑的天然石墨粉也可做為鋰離子電池的負極材 201240197 料。 姑本發明是將微小的球形天然石墨粉1〜ίο卿，與高分子 ^脂混合後’姻鱗乾燥的造粒與乾轉性製作成粒徑 、秘〜25㈣且表面包覆一層高分子聚合物薄膜，或經碳化 之賴的石墨複合材，其石墨表面多了這層薄職，可以 抑制與降低鈍化難電解賴造成的不可逆電容量損失， 其循環壽命與電容量也較天然石難，加上本發明採 用負極材料廠生產時所產生的石墨細粉廢料，其目前商業 上尚無採隸㈣為KH) μιη賴粉做為_子電池負極材 料，因此本發明除了能夠提升負極材料的性能外並且有廢 物再利用的成效，對於降低生產成本有很大的助益。 表1 :為對於不同實施例與比較例1中石墨負極材之電 性比較之總整理，由表可知實施例1有較佳的充放電性與 庫倫效率，可視為一種鋰離子電池負極材。 表2 :為對於不同實施例與比較例1中石墨負極材之比 表面積與平均粒徑比較，由表可知原本為1〜3 μπ!的石墨 粉體’經高分子樹脂混合後’經喷霧乾燥的造粒與乾燥特 性，製作成粒徑約18〜20 μιη且比表面積為1.8〜2 rr^g·1的石墨 複合材。 本發明之優勢為使石墨與高分子樹脂的結合更為密 合，高分子樹脂均勻的包覆於石墨表面，將石墨表面缺陷 補平，又可將細小的石墨粉顆粒相互連結，形成較大的類 球型顆粒粉體，其可以防止SEI膜脫落’改善電解液不相 容問題，因而使不可逆電容量降低，庫倫效率增加，穩定 201240197 的循環壽命與較高的充放電電容量。 表1不同實施例與比較例1中石墨負極材之電性比較 項 g 石墨粒徑 (μιη) 包覆高分子 材種類 第1次 充電 電容量 (mAh/g) 第1次 放電 電容量 (mAh/g) 第1次 庫倫 效率 (%) 第50次 充電 電容量 (mAh/g) 第50次 放電 電容量 (mAh/g) 比較 例1 3 μιη PVB 400.8 341.8 85.2 340.6 322.8 實施 例1 3 μηι PAA 399.6 360.0 90.0 364.6 358.5 實施 例2 1 μιη PEDOT 379.1 348.8 92.0 350.6 346.8 實施 例3 實施 例4 2 μηι -----—. 水性紛經 樹脂 388.4 348.7 89.8 355.8 346.2 15 μηι PEDOT 377.2 341.5 90.5 353.5 339.1 表2不同實施例與比較例1中石墨包覆樹脂後經喷霧乾燥 後之比表面積與粒徑比較 項目 平均粒徑D50 (μηι) 比表面積(m2g-、 比較例]. 19.95 μηι 2.15 mV' 實施例1. 18.99 μηι 1.91 mV 實施例2. 18.29 nm 1.83 m2g*' 實施例3. 19.77 μηι 2.32 mV 實施例4. 19.35 μηι 1.89 mV' 藉此可知’本發明石墨微粉應用於鋰離子電池負極材 料及其製備方法’係先將天然石墨與高分子樹脂攪拌混 合’由其粒徑約為1〜10 μιη的球形石墨細粉，與高分子樹脂 此合成聚體’再由喷霧乾燥機製作成15〜25 μπι顆粒狀粉體 後製作獲得表面改質碳材之石墨複合碳材，藉以解決習 201240197 :之，炭材料(例如：天然石墨、煤炭、碳纖 穩相球狀碳MCMB)之具充放電速度慢 汙染及價料貴等缺點。 ㊆m w兄 明，=:===::實施例之具趙說 離本發明技藝精神所為之 案之專利範圍中。 羑更，均應包含於本 【圖式簡單說明】 後之示^顿駭合後經喷霧乾燥 S複合材H妹圖；以及 量圖第3圖為本發明石墨複合碳材％次放電循環次數電容 【主要元件符號說明】S 6 201240197 The following are descriptions of comparative examples and examples to illustrate the features and advantages of the present invention, first described with respect to Comparative Example 1, and then comparative examples to Examples 4 to demonstrate the effects of the present invention. Comparative Example 1: Mixing an average particle size of 3 μηη natural graphite powder with alcohol to a deflocculant to adjust the solid content to 30 to 50 wt%, and then adding 5% by weight of polyvinyl butyral (pVB) as a graphite powder. After the binder is stirred in the stirring tank for 2 to 5 hours, it is dried by a spray dryer, granulated, and heat-treated by a carbonization furnace, wherein the heat treatment temperature is 600~1 〇〇〇<t, and the obtained powder is used as a powder. Ion negative electrode material, and the method of coating and battery assembly is as follows. Mix 0_1 wt% trace oxalic acid with 1〇wt〇/0 polyvinylidene fluoride (pvDF) binder (Binder) into N-mercaptopyrrolidone (NMP) solvent, uniformly stirred for 20 minutes, so that the polyvinylidene fluoride can be uniformly dispersed in the solvent mixture; the graphite carbon powder is placed in the uniformly stirred mixture, and the mixture is continuously stirred for 20 minutes. The liquid is formed into a slurry, uniformly coated on a copper foil with a 13 〇μη squeegee, and dried at 10 (rC to remove residual solvent, crushed at a rolling ratio of 25%, and then dried by n (rc). The assembly part first cuts the negative electrode piece of the coating element into a circular plate with a diameter of 13 cm. Lithium metal foil is used; the components required for the coin-shaped battery are assembled sequentially in the dry atmosphere control room, and an electrolyte solution (1M clock hexafluoride (LiPF6) (solute)_ethylene carbonate (EC) is added. / Ethyl carbonate (EMC) (solvent) (Volume 1:2)), that is, complete a coin-shaped battery; assembled coin-type battery for continuous charge and discharge performance test, its charge and discharge rate is 0.2C constant current density Continuous charging and discharging 5 times, the charging voltage is 2V (vs· Li / U+ ), and the discharge voltage is 〇〇〇5v 201240197 (vs. Li / Li ). Its first charging capacity is 400.8 mAh/g. The discharge capacity was 341.8 mAh/g 'coulomb efficiency was 85.2%. The 50th charge capacity was 340.6 mAh/g' discharge capacity was 322.8 mAh/g. Example 1: Natural graphite with an average particle size of 3 μm 〇g and 〇.9g of resin polyacrylamide (PAA) is added to deionized water and mixed and stirred for 1~5 hours. After mixing into a slurry, spray drying machine is used to dry and granulate. The dry inlet temperature is 28 〇. (:, the outlet temperature is 15 (TC, available after drying) The composite graphite powder with a particle size of about 15~25 μηη can be used as a negative electrode material. The preparation method of the battery is the same as the capacitance test. The first charge capacity of this material is 399.6 mAh/g, and the discharge capacity is 36〇mAh/g, Coulomb efficiency is 90%. The 50th charge capacity is 364 6 mAh/g 'discharge capacity is 358.5 mAh/g. Comparing the above experiments, the discharge capacity of Example 1 and Coulomb are known. The efficiency and cycle stability were significantly better than those of Comparative Example 1. Example 2: 3 〇g of natural graphite powder with a particle size of 1 μηη and 3.6g of poly(3,4-ethylenedioxythiophene) (PED〇T) resin were mixed into a sufficient amount of deionized water, and the stirring time was 1~5 hours, after mixing into a slurry, spray drying machine is used for drying and granulation. The spray drying inlet temperature is 28 (^c, the outlet temperature is 150 C dry, and the particle size is about 1 $. ~25 μηι composite graphite powder can be used as a negative electrode material, and its battery preparation method and capacitance test are the same as in Comparative Example 1. The first charge capacity of this material is 379.1 mAh/g, and the discharge capacity is 348.8 mAh/g. The Coulomb efficiency is 92%. The 50th charge capacity is 350.6 mAh/g, and the discharge capacity is 346.8 mAh/g. The cycle and discharge capacity are also significantly improved and stable compared to Comparative Example 1. 201240197 Example 3: 30 g of natural graphite with a particle size of 2 μm and 3 g of aqueous phenolic resin, mixed with deionized water, and mixed for 1 to 5 hours. After mixing into a slurry, spray drying is used to dry and granulate. Dry inlet temperature is 28 (TC, outlet temperature is 150 ° C, can be obtained after drying The composite graphite powder with a diameter of about 15~25 μπι is then passed through 1250. (: After carbonization heat treatment, it can be used as a negative electrode material, and the preparation method and capacitance test of the battery are the same as in Comparative Example 1. The first charge capacity of the material It is 388.4 mAh/g, the discharge capacity is 348.7 mAh/g, the coulombic efficiency is 89.8%, the 50th charge capacity is 355.8 mAh/g, the discharge capacity is 346.2 mAh/g, and the capacitance of Comparative Example 1 is also compared. Large and stable. Example 4: Mixing 15 μm of natural graphite 3〇g with 6.6g of poly 3,4-ethylenedioxythiophene (PEDOT) resin in deionized water, stirring for 1~5 hours, mixing After the slurry is formed, the spray dryer is used for drying. The spray drying inlet temperature is 280t, and the outlet temperature is 15〇. (: After drying, the composite graphite powder with a particle size of about 18~20 μm can be obtained, which can be used as a negative electrode. For the use of materials, the preparation method of the battery is the same as the capacitance test. The first charge of this material is 377.2 mAh/g, the discharge capacity is 3415 mAh/g, and the Coulomb ratio is 90.5%. The charging capacity is 360 5 mAh/g, and the discharge capacity is 339.1. mAh/g. Combining the above experiments, we can understand the properties of the natural graphite coated polymer resin with the particle size of 15~18 μηη and the Coulomb efficiency when coated with the same and equal amount of polymer tree. It is quite close to the nature of the polymer resin coated with natural graphite fine powder with a fine particle size of 1~10 μm, so it can be further confirmed that the fine graphite powder of natural particle size can also be used as the negative electrode material 201240197 of lithium ion battery. The invention is a small spherical natural graphite powder 1~ίοqing, mixed with a polymer compound, and then granulated and dried to form a particle size, secret ~ 25 (four) and coated with a layer of polymer The film or the carbonized graphite composite has a thin surface on the graphite surface, which can suppress and reduce the irreversible capacity loss caused by the hardening of the passivation. The cycle life and capacitance are also more difficult than natural stones. The present invention adopts graphite fine powder waste produced by the production of the negative electrode material factory, and currently there is no commercially available (4) KH) μιη Lai powder as the anode material of the sub-battery, so the invention can improve the performance of the anode material. The effectiveness of waste recycling is also very helpful in reducing production costs. Table 1 is a total comparison of the electrical properties of the graphite negative electrode materials of the different examples and Comparative Example 1. It can be seen from the table that Example 1 has better charge and discharge properties and coulombic efficiency, and can be regarded as a lithium ion battery negative electrode material. Table 2: For the comparison of the specific surface area and the average particle diameter of the graphite negative electrode material in the different examples and Comparative Example 1, it is known from the table that the graphite powder of the original 1 to 3 μπ! is mixed with the polymer resin. Dry granulation and drying characteristics were prepared into a graphite composite having a particle diameter of about 18 to 20 μm and a specific surface area of 1.8 to 2 rr^g·1. The invention has the advantages that the bonding of the graphite and the polymer resin is more closely combined, the polymer resin is uniformly coated on the surface of the graphite, the surface defects of the graphite are filled up, and the fine graphite powder particles are connected to each other to form a larger one. The ball-like particle powder, which prevents the SEI film from falling off, improves the electrolyte incompatibility problem, thereby reducing the irreversible capacity, increasing the coulombic efficiency, stabilizing the cycle life of 201240197 and the higher charge and discharge capacity. Table 1 Comparison of electrical properties of graphite negative electrode materials in different examples and Comparative Example 1 g Graphite particle size (μιη) Type of coated polymer material 1st charge capacity (mAh/g) 1st discharge capacity (mAh) /g) 1st Coulomb efficiency (%) 50th charge capacity (mAh/g) 50th discharge capacity (mAh/g) Comparative Example 1 3 μηη PVB 400.8 341.8 85.2 340.6 322.8 Example 1 3 μηι PAA 399.6 360.0 90.0 364.6 358.5 Example 2 1 μη PEDOT 379.1 348.8 92.0 350.6 346.8 Example 3 Example 4 2 μηι ------. Aqueous resin 388.4 348.7 89.8 355.8 346.2 15 μηι PEDOT 377.2 341.5 90.5 353.5 339.1 Table 2 Comparison of specific surface area and particle diameter of spray-dried graphite coated resin in different examples and Comparative Example 1 Item Average particle diameter D50 (μηι) Specific surface area (m2g-, Comparative Example). 19.95 μηι 2.15 mV' Example 1. 18.99 μηι 1.91 mV Example 2. 18.29 nm 1.83 m2g*' Example 3. 19.77 μηι 2.32 mV Example 4. 19.35 μηι 1.89 mV' It is understood that the graphite micropowder of the present invention is applied to a lithium ion battery anode material and system The method 'firstly mixes natural graphite with a polymer resin' from a spherical graphite fine powder having a particle diameter of about 1 to 10 μm, and a synthetic polymer with a polymer resin, and then a spray dryer to make 15 to 25 μπι. After the granular powder is prepared, the graphite composite carbon material obtained by obtaining the surface modified carbon material is used to solve the problem of slow charging and discharging of the carbon material (for example, natural graphite, coal, carbon fiber stable phase spherical carbon MCMB). And the price of expensive and other shortcomings. Seven m w brother Ming, =: ===:: The embodiment of the Zhao said that the patent is within the scope of the patent. The 羑,, should be included in this [simple Explanation] After the display, the spray-dried S composite H-picture is shown; and the figure 3 is the graphite composite carbon material % discharge cycle number capacitance [main component symbol description]