JP4684727B2 - Positive electrode material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery - Google Patents
Positive electrode material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery Download PDFInfo
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- 239000007774 positive electrode material Substances 0.000 title claims description 86
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims description 35
- 229910001416 lithium ion Inorganic materials 0.000 title claims description 35
- 238000004519 manufacturing process Methods 0.000 title claims description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 143
- 229910052799 carbon Inorganic materials 0.000 claims description 118
- 239000002245 particle Substances 0.000 claims description 115
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 81
- 229910010707 LiFePO 4 Inorganic materials 0.000 claims description 76
- 238000000034 method Methods 0.000 claims description 43
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- 229910052744 lithium Inorganic materials 0.000 claims description 16
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 15
- 238000002230 thermal chemical vapour deposition Methods 0.000 claims description 14
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 12
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Battery Electrode And Active Subsutance (AREA)
Description
本発明はリチウムイオン二次電池用正極材料及びその製造方法、並びにその正極材料を用いてなるリチウムイオン二次電池に関する。 The present invention relates to a positive electrode material for a lithium ion secondary battery, a manufacturing method thereof, and a lithium ion secondary battery using the positive electrode material.
リチウムイオン二次電池は、軽量でエネルギー密度が高いことから、民生用では、ＩＴ情報端末を中心に携帯電話、ノート型パソコン、バックアップ電源の小型電池に幅広く使用されている。現在もその需要が世界的な規模で伸びている。 Lithium ion secondary batteries are lightweight and have a high energy density, and are therefore widely used in consumer applications, mainly in IT information terminals, for mobile phones, laptop computers, and small batteries for backup power supplies. Today, the demand is growing on a global scale.
この小型電池に加えて、産業用の大型電池としても、ハイブリッド自動車用、電気自動車用、電力平準化用、電力貯蔵用、ロボット用など多方面に、その需要が今後期待され、研究開発も盛んに行われている。 In addition to these small batteries, industrial large batteries are also expected to be used in various fields such as hybrid cars, electric cars, power leveling, power storage, and robots, and research and development are thriving. Has been done.
このような状況下で産業用の大型電池が本格的に実用化されるための課題として、正極材料には、高い安全性、高寿命、高出力、低価格が要求されている。その中で高い安全性と優れたサイクル性能を示し、低価格で製造可能なＬｉＦｅＰＯ4がＬｉＣｏＯ2、ＬｉＭｎ2Ｏ4代替正極材料として注目されている。 Under such circumstances, high safety, long life, high output, and low price are required for the positive electrode material as a problem for full-scale commercialization of large industrial batteries. Among them, LiFePO 4 , which exhibits high safety and excellent cycle performance and can be manufactured at a low price, has attracted attention as an alternative positive electrode material for LiCoO 2 and LiMn 2 O 4 .
従来のＬｉＦｅＰＯ4の合成は、合成原料となるＦｅ源はシュウ酸鉄ＦｅＣ2Ｏ4、燐酸鉄Ｆｅ3(ＰＯ4)2や酢酸鉄Ｆｅ(ＣＨ3ＣＯＯ)2などの２価の鉄塩を用い、リチウム化合物や燐酸アンモニウム塩とともに還元雰囲気下で高温焼成することで合成されていた。 In the conventional synthesis of LiFePO 4, the Fe source as a synthesis raw material is a divalent iron salt such as iron oxalate FeC 2 O 4 , iron phosphate Fe 3 (PO 4 ) 2 or iron acetate Fe (CH 3 COO) 2. It was synthesized by firing at a high temperature in a reducing atmosphere together with a lithium compound and ammonium phosphate.
しかしながら、ＬｉＦｅＰＯ4合成に使用する原料は、大量且つ容易に入手可能であることが必要であるが、シュウ酸鉄ＦｅＣ2Ｏ4、酢酸鉄Ｆｅ(ＣＨ3ＣＯＯ)2などは原料自身の毒性や高価格などの欠点があり、取扱い上あるいは安定供給に問題がある。Ｆｅ3(ＰＯ4)2については、繰り返し洗浄が必要なうえに、Ｎａが残留する問題があるので好ましくない。 However, the raw materials used for LiFePO 4 synthesis need to be easily available in large quantities, but iron oxalate FeC 2 O 4 , iron acetate Fe (CH 3 COO) 2, etc. There are drawbacks such as high price, and there are problems in handling and stable supply. Fe 3 (PO 4 ) 2 is not preferable because it requires repeated washing and Na remains.
このような観点から、ＬｉＦｅＰＯ4合成用の原料としては、鉄あるいは酸化鉄が好ましいと考えられる。鉄を原料として合成する方法が特許文献１で提案されている。この方法は安価で合成可能であるが、液相で前躯体を調製するために、廃液の処理が必要であり、また、焼成時に多量の塩素が発生するため、環境面からも好ましくない。
From such a viewpoint, it is considered that iron or iron oxide is preferable as a raw material for LiFePO 4 synthesis.
一方、２価、３価の酸化鉄から単相のＬｉＦｅＰＯ4を合成した例はなく、特許文献２、特許文献３で鉄粉や炭素粉末などの還元助剤を添加したり、焼成時の雰囲気を制御したりして２価の鉄から３価の鉄への酸化抑制が検討されてきている以外に検討された例はない。これは、２価、３価の酸化鉄の還元状態を制御することが難しく、還元力が強い場合は鉄になり、弱い場合は、酸化状態で存在するためである。酸化鉄からの合成の場合、焼成時に酸化鉄の還元によって生成されるのは、ＣＯ2のみであるので、環境に良いと考えられる。このように、ＬｉＦｅＰＯ4合成用原料については、安価な酸化鉄を還元してＬｉＦｅＰＯ4を合成する方法が最も好ましいと考えられる。 On the other hand, there is no example of synthesizing single-phase LiFePO 4 from divalent or trivalent iron oxide. In Patent Documents 2 and 3, a reducing aid such as iron powder or carbon powder is added, or the atmosphere during firing. There is no example examined other than controlling oxidation from divalent iron to trivalent iron by controlling the above. This is because it is difficult to control the reduced state of divalent and trivalent iron oxide, and when the reducing power is strong, it becomes iron, and when it is weak, it exists in the oxidized state. In the case of synthesis from iron oxide, it is considered that it is good for the environment because only CO 2 is produced by reduction of iron oxide during firing. Thus, with regard to the LiFePO 4 synthesis raw material, a method of synthesizing LiFePO 4 by reducing inexpensive iron oxide is considered most preferable.
ＬｉＦｅＰＯ4への導電性の付与方法については、２つの方法が提案されている。１つ目の方法は、粒子内部の導電性を改善するもので、合成原料中に非晶質カーボン、黒鉛などの導電性付与材料を混合して焼成することによって導電性を改善するものである。これについては、特許文献４、特許文献５、特許文献６、特許文献７など多くの特許が出願されているが、ＬｉＦｅＰＯ4粒子表面への炭素の析出はほとんどない。なお、電気は材料の表面にも流れる場合、その材料は低抵抗を示す。そのため、特許文献４〜７の方法では、ＬｉＦｅＰＯ4粒子は高抵抗のものとなり、実用的なものは得られていない。
Two methods have been proposed for imparting conductivity to LiFePO 4 . The first method is to improve the conductivity inside the particles, and to improve the conductivity by mixing and firing a conductivity-imparting material such as amorphous carbon and graphite in the synthetic raw material. . Regarding this, many patents such as Patent Document 4, Patent Document 5,
２つ目の方法は、ＬｉＦｅＰＯ4粒子に対する導電性付与を粒子内部と表面を同時に行うものである。この方法は、合成原料と気化成分を含む炭素前躯体、例えば石炭タール、ピッチ、糖類などとを混合して、焼成することによって、炭素前躯体の非気化分はそのまま粒子内部に炭素として残し、気化分の炭素を粒子表面に沈着させて粒子表面を炭素で被覆しようとするものであり、特許文献８で提案されている。この方法によれば、粒子の内部には非気化炭素が含有され、粒子の外部には気化炭素が被覆されるので、導電性は上記１つ目の方法に比較して向上する。 In the second method, conductivity is imparted to the LiFePO 4 particles simultaneously on the inside and on the surface of the particles. In this method, a carbon precursor containing a synthetic raw material and a vaporizing component, for example, coal tar, pitch, saccharides, and the like are mixed and baked, so that the non-vaporized content of the carbon precursor is left as carbon inside the particles as it is, The vaporized carbon is deposited on the particle surface to cover the particle surface with carbon, which is proposed in Patent Document 8. According to this method, since non-vaporized carbon is contained inside the particles and vaporized carbon is coated on the outside of the particles, the conductivity is improved as compared with the first method.
しかし、特許文献８の方法は一般的に固定床で焼成が行われるため、ＬｉＦｅＰＯ4粒子表面を均一にしかも完全に炭素で被覆することは難しく、ラマン分光法などで測定するとＬｉＦｅＰＯ4由来の９００〜１２００ ｃｍ-1にピークが強く現れ、ＬｉＦｅＰＯ4表面が炭素で完全に被覆されていないことを示す。この原因としては、以下の２つのことが要因として考えられる。 However, since the method of Patent Document 8 is generally fired in a fixed bed, it is difficult to uniformly and completely cover the surface of LiFePO 4 particles with carbon. When measured by Raman spectroscopy or the like, 900 derived from LiFePO 4 is used. A strong peak appears at ˜1200 cm −1 , indicating that the LiFePO 4 surface is not completely covered with carbon. There are two possible causes for this.
(１) 焼成時に粒子が移動しないため、炭素前躯体や石炭タールから発生した炭素により粒子同士の接着が起こり、これが焼成後の解砕、混合処理によって接点で剥離を生じてボイドとなり、ＬｉＦｅＰＯ4表面が現れる。 (1) Since the particles do not move during firing, adhesion between the particles occurs due to the carbon generated from the carbon precursor or coal tar, which causes separation at the contact points by crushing and mixing treatment after firing, resulting in voids, and LiFePO 4 The surface appears.
(２) 焼成時に粒子が積層されて焼成されるため、上層と下層及び中心とエッジでは、ガスの流れが均一でなくなり、炭素の付着の多い部分と少ない部分が存在する。 (2) Since particles are laminated and fired at the time of firing, the gas flow is not uniform in the upper layer and the lower layer, and in the center and the edge, and there are portions where carbon adheres more and less.
ＨＥＶ(ハイブリッド自動車)用などの電池では、回生、出力エネルギーに５０〜２００Ｃ程度のレートが必要である。このような用途の電池材料としては、材料の表面に大きな電気を流す必要があり、そのため、材料が発熱しないために、低抵抗の材料が好ましい。そのために、材料粒子表面を低抵抗の材料で被覆することが好ましく、現実的には、炭素で完全に被覆した材料が求められている。
本発明者らは、まず酸化鉄の還元剤としてアスコルビン酸や非晶質炭素、石炭タールを用いてＬｉＦｅＰＯ4の合成を試みた。アスコルビン酸については、還元力が強かったため鉄金属が生成し鉄相とＬｉＦｅＰＯ4相との複合相となり、単相のＬｉＦｅＰＯ4は得られなかった。非晶質炭素を用いた場合は還元力が低く、合成されたＬｉＦｅＰＯ4は、酸化鉄との混合状態であり、単相のＬｉＦｅＰＯ4が得られず、材料そのものの導電性が低かった。石炭タールについては、単相のＬｉＦｅＰＯ4に近い結晶性を示すものが合成可能であったが、表面の炭素被覆状態が悪いため、導電性が低く充放電出力の低い材料であった。また、非晶質炭素と石炭タールを組み合わせた場合も同様に充放電出力の大きな改善は認められなかった。 The present inventors first attempted to synthesize LiFePO 4 using ascorbic acid, amorphous carbon, and coal tar as a reducing agent for iron oxide. Ascorbic acid was strong in reducing power, and iron metal was produced to form a composite phase of an iron phase and a LiFePO 4 phase, and no single-phase LiFePO 4 was obtained. When amorphous carbon was used, the reducing power was low, and the synthesized LiFePO 4 was in a mixed state with iron oxide, so that single-phase LiFePO 4 was not obtained, and the conductivity of the material itself was low. As for coal tar, a material showing crystallinity close to that of single-phase LiFePO 4 could be synthesized. However, since the surface carbon coating state was poor, the material was low in conductivity and low in charge / discharge output. Similarly, when amorphous carbon and coal tar were combined, no significant improvement in charge / discharge output was observed.
このため、本発明者らは、酸化鉄の還元に有効な還元性を示し、さらに、合成原料に混合した場合に高導電性を示す導電材料について探索し、加えてＬｉＦｅＰＯ4表面を炭素で被覆する方法について鋭意研究を重ねた結果、酸化鉄の還元材、材料の導電材として黒鉛が有用であり、且つ材料表面を流動床熱ＣＶＤ(化学蒸着処理)法により、単相のＬｉＦｅＰＯ4が得られ、その表面を炭素で均一の被覆することが可能であることを見出した。また、当該材料は電池試験において極めて良好な充放電出力特性を示し、ＨＥＶ用正極材料として好適であると判断された。 For this reason, the present inventors have searched for conductive materials that exhibit effective reducibility for reducing iron oxide and that exhibit high conductivity when mixed with synthetic raw materials, and in addition, cover the surface of LiFePO 4 with carbon. As a result of earnest research on the method to perform, graphite is useful as a reducing material of iron oxide and a conductive material of the material, and a single-phase LiFePO 4 is obtained by fluidized bed thermal CVD (chemical vapor deposition) method on the material surface. And found that it is possible to uniformly coat the surface with carbon. Moreover, the said material showed the very favorable charging / discharging output characteristic in the battery test, and it was judged that it was suitable as a positive electrode material for HEV.
酸化鉄、リチウム化合物、燐酸化合物と反応させてＬｉＦｅＰＯ4を合成しようとする試みは以前からあったが、ＬｉＦｅＰＯ4の合成と粒子の導電性の両方の物性を１度の処理で発現させようとするあまりに、酸化鉄の還元力が強い場合、鉄が生成し、還元力が弱い場合は、酸化鉄のまま残るため、単相のＬｉＦｅＰＯ4の合成は困難であった。そこで、本発明者らは、上記の課題を達成するために、下式のように、まず(１)酸化鉄を還元剤で良好に還元する反応［化１］、(２)粒子に導電性を与える反応［化２］の２段階反応を考えた。 There have been attempts to synthesize LiFePO 4 by reacting with iron oxide, lithium compounds, and phosphoric acid compounds. However, both the synthesis of LiFePO 4 and the electrical conductivity of the particles should be expressed by a single treatment. When the reducing power of iron oxide is too strong, iron is generated, and when the reducing power is weak, iron oxide remains, so that it is difficult to synthesize single-phase LiFePO 4 . Therefore, in order to achieve the above-mentioned problems, the present inventors firstly (1) a reaction for satisfactorily reducing iron oxide with a reducing agent [Chemical Formula 1], and (2) particles having conductivity. A two-step reaction of [Chem.
次に、このＬｉＦｅＰＯ4を流動層で熱ＣＶＤ処理を施すことにより、ＬｉＦｅＰＯ4粒子表面へ熱ＣＶＤ炭素膜を生成させることにより、高導電性の炭素で完全に被覆したＬｉＦｅＰＯ4核粒子と炭素層の２層構造の複合粒子が得られると考え、本発明に至った。 Next, the LiFePO 4 core particles and the carbon layer completely covered with highly conductive carbon are formed by subjecting this LiFePO 4 to thermal CVD treatment in a fluidized bed to generate a thermal CVD carbon film on the surface of the LiFePO 4 particles. It was considered that composite particles having a two-layer structure were obtained, and the present invention was achieved.
即ち、鉄原料として酸化鉄を用い、還元剤として導電性の高い黒鉛を使用することにより、安価にＬｉＦｅＰＯ4を合成し、その表面を流動層熱ＣＶＤ法により均一に炭素で被覆することにより、高導電性を有するＬｉＦｅＰＯ4核と炭素層の２層構造複合体を有するＨＥＶ用リチウム二次電池正極材料として好適なＬｉＦｅＰＯ4と炭素の複合体を得ることができた。 That is, by using iron oxide as an iron raw material and using highly conductive graphite as a reducing agent, LiFePO 4 is synthesized at low cost, and its surface is uniformly coated with carbon by a fluidized bed thermal CVD method. A composite of LiFePO 4 and carbon suitable as a positive electrode material for a lithium secondary battery for HEV having a two-layer composite of a LiFePO 4 nucleus and a carbon layer having high conductivity could be obtained.
以上のように、本発明の目的は、上記問題を解決した、ＨＥＶ用実電池として高充放電特性に優れるＬｉＦｅＰＯ4系正極材料を安価、多量に提供することにある。 As described above, an object of the present invention is to provide a LiFePO 4 -based positive electrode material excellent in high charge / discharge characteristics as a HEV real battery that solves the above-described problems at low cost and in large quantities.
上記目的を達成する本発明は、以下に記載するものである。 The present invention for achieving the above object is described below.
〔１〕 ＬｉＦｅＰＯ4粒子及び炭素で形成された凝集粒子と、その凝集粒子の外側を被覆した炭素層との２層構造の複合粒子であり、ラマン分光法で１５８０ｃｍ-1のピーク強度Ｇに対する１３６０ｃｍ-1のピーク強度Ｃの比(Ｃ／Ｇ)が０．５以下であり、且つ１５８０ｃｍ-1のピーク強度Ｇに対する９００〜１２００ｃｍ-1のピーク強度Ｆの比(Ｆ／Ｇ)が０．１以下であるリチウムイオン二次電池用正極材料。 [1] A composite particle having a two-layer structure of agglomerated particles formed of LiFePO 4 particles and carbon and a carbon layer covering the outside of the agglomerated particles, and 1360 cm for a peak intensity G of 1580 cm −1 by Raman spectroscopy. the ratio of the peak intensity C of -1 (C / G) is 0.5 or less, and the ratio of the peak intensity F of 900～1200Cm -1 to the peak intensity G of 1580 cm -1 (F / G) is 0.1 The positive electrode material for lithium ion secondary batteries which is the following.
〔２〕 平均粒度が１〜２０μｍ、比表面積が１〜５０ｍ2／ｇ、タップ密度が０．６〜１．６ｇ／ｃｍ3である〔１〕に記載のリチウムイオン二次電池用正極材料。 [2] The positive electrode material for a lithium ion secondary battery according to [1], having an average particle size of 1 to 20 μm, a specific surface area of 1 to 50 m 2 / g, and a tap density of 0.6 to 1.6 g / cm 3 .
〔３〕 一般式ＦｅｘＯｙ(０＜ｘ≦３、０＜ｙ≦４)で表される酸化鉄と、黒鉛と、リチウム源と、燐源との混合物を不活性ガス中６００〜９００℃で加熱してＬｉＦｅＰＯ4粒子及び炭素で形成された凝集粒子を得、次いで前記凝集粒子を流動層熱ＣＶＤ法で処理する、ＬｉＦｅＰＯ4粒子及び炭素で形成された凝集粒子と、その凝集粒子の外側を被覆した炭素層との２層構造の複合粒子であり、ラマン分光法で１５８０ｃｍ-1のピーク強度Ｇに対する１３６０ｃｍ-1のピーク強度Ｃの比(Ｃ／Ｇ)が０．５以下であり、且つ１５８０ｃｍ-1のピーク強度Ｇに対する９００〜１２００ｃｍ-1のピーク強度Ｆの比(Ｆ／Ｇ)が０．１以下であるリチウムイオン二次電池用正極材料の製造方法。 [3] A mixture of iron oxide represented by the general formula FexOy (0 <x ≦ 3, 0 <y ≦ 4), graphite, lithium source, and phosphorus source is heated at 600 to 900 ° C. in an inert gas. To obtain agglomerated particles formed of LiFePO 4 particles and carbon, and then the agglomerated particles are processed by a fluidized bed thermal CVD method. The agglomerated particles formed of LiFePO 4 particles and carbon are coated on the outside of the agglomerated particles. a composite particle of the two-layer structure of a carbon layer, the ratio of the peak intensity C of 1360 cm -1 to the peak intensity G of 1580cm -1 in Raman spectroscopy (C / G) is not less than 0.5, and 1580cm -1 ratio of the peak intensity F of 900～1200Cm -1 to the peak intensity G of (F / G) is method for producing a cathode material for a lithium ion secondary battery is 0.1 or less.
〔４〕 黒鉛の質量比が酸化鉄とリチウム源と燐源との合計量に対して３〜２０質量％である〔３〕に記載のリチウムイオン二次電池用正極材料の製造方法。 [4] The method for producing a positive electrode material for a lithium ion secondary battery according to [3], wherein a mass ratio of the graphite is 3 to 20% by mass with respect to a total amount of the iron oxide, the lithium source, and the phosphorus source.
〔５〕 〔１〕に記載のリチウムイオン二次電池用正極材料を含む正極を有するリチウムイオン二次電池。 [5] A lithium ion secondary battery having a positive electrode including the positive electrode material for a lithium ion secondary battery according to [1].
本発明のリチウムイオン二次電池用正極材料は、ＬｉＦｅＰＯ4粒子及び炭素で形成された凝集粒子を核粒子ＬｉＦｅＰＯ4として流動層熱ＣＶＤ法で被覆処理しているので、ラマン分光スペクトルは上記のピーク分布を示し、上記凝集粒子の表面は結晶性の炭素で均一に被覆されているので電気抵抗が低い。そのため、当該正極材料は電池試験において極めて良好な充放電出力特性を示し、ＨＥＶ用正極材料として好適である。 The positive electrode material for a lithium ion secondary battery according to the present invention is obtained by coating LiFePO 4 particles and agglomerated particles formed of carbon as core particles LiFePO 4 by a fluidized bed thermal CVD method. It shows a distribution, and the surface of the aggregated particles is uniformly coated with crystalline carbon, so that the electric resistance is low. Therefore, the positive electrode material exhibits extremely good charge / discharge output characteristics in a battery test and is suitable as a positive electrode material for HEV.
本発明の製造方法によれば、核粒子ＬｉＦｅＰＯ4の合成に際し、酸化鉄と、酸化鉄の還元材として黒鉛とを用いているので、上記核粒子ＬｉＦｅＰＯ4を得ることが可能である。 According to the production method of the present invention, when the synthesis of the particulate core LiFePO 4, iron oxide, because of the use of graphite as a reducing agent of iron oxide, it is possible to obtain the core particles LiFePO 4.
また、上記正極材料を用いて形成された本発明のリチウムイオン二次電池は、高容量、高出力の優れた物性を示す。 Moreover, the lithium ion secondary battery of the present invention formed using the positive electrode material exhibits excellent physical properties such as high capacity and high output.
以下、本発明について更に詳しく説明する。 Hereinafter, the present invention will be described in more detail.
本発明のリチウムイオン二次電池用正極材料は、ＬｉＦｅＰＯ4核粒子と、その表面を覆う炭素層の２層構造の複合粒子である。前記正極材料は、ラマン分光法で１５８０ｃｍ-1のピーク強度Ｇに対する１３６０ｃｍ-1のピーク強度Ｃの比(Ｃ／Ｇ)が０．５以下であり、且つ１５８０ｃｍ-1のピーク強度Ｇに対する９００〜１２００ｃｍ-1のピーク強度Ｆの比(Ｆ／Ｇ)が０．１以下である。 The positive electrode material for a lithium ion secondary battery of the present invention is a composite particle having a two-layer structure of LiFePO 4 core particles and a carbon layer covering the surface thereof. The positive electrode material, the ratio of the peak intensity C of 1360 cm -1 to the peak intensity G of 1580 cm -1 in Raman spectroscopy (C / G) is 0.5 or less, and 900 to the peak intensity G of 1580 cm -1 The ratio (F / G) of the peak intensity F at 1200 cm −1 is 0.1 or less.
本発明のＬｉＦｅＰＯ4正極材料の好適な平均粒度は１〜２０μｍ、比表面積は１〜５０ｍ2／ｇ、タップ密度は０．６〜１．６ｇ／ｃｍ3である。 The preferred average particle size of the LiFePO 4 positive electrode material of the present invention is 1 to 20 μm, the specific surface area is 1 to 50 m 2 / g, and the tap density is 0.6 to 1.6 g / cm 3 .
ＬｉＦｅＰＯ4表面のラマン分析スペクトルは９００〜１２００ｃｍ-1(Ｆ)に複数のピークを示す。また、非晶質炭素は１３６０ｃｍ-1(Ｃ)に結晶質炭素は１５８０ｃｍ-1(Ｇ)にピークを示す。従って、ＬｉＦｅＰＯ4表面を炭素で完全に覆っている場合は、９００〜１２００ ｃｍ-1のピークの出現はなく、１３６０ｃｍ-1、１５８０ｃｍ-1のピークのみとなる。この場合、被覆されているかどうかの尺度としてピーク強度比Ｆ／Ｇをとると、このＦ／Ｇの値が０に近づくほど完全な被覆と定義可能である。また、非晶質、結晶質の判断は、ピーク強度比Ｃ／Ｇを算出することで容易に表すことが可能である。この場合もＣ／Ｇの値が０に近づくほど結晶質ということができる。理想的には、炭素被覆はＦ／Ｇ、Ｃ／Ｇが０に近い材料程、導電性が良い。 The Raman analysis spectrum of the LiFePO 4 surface shows a plurality of peaks at 900 to 1200 cm −1 (F). Amorphous carbon has a peak at 1360 cm −1 (C) and crystalline carbon has a peak at 1580 cm −1 (G). Therefore, if you are completely covers the LiFePO 4 surface with carbon, rather than the appearance of a peak of 900 to 1200 cm -1, and only the peak of 1360 cm -1, 1580 cm -1. In this case, when the peak intensity ratio F / G is taken as a measure of whether or not the coating is applied, it can be defined as a complete coating as the F / G value approaches zero. In addition, the determination of amorphous or crystalline can be easily expressed by calculating the peak intensity ratio C / G. Also in this case, the closer the C / G value is to 0, the more crystalline it can be said. Ideally, the carbon coating has better conductivity as the material with F / G and C / G closer to 0.
近年、リチウムイオン電池では、正極材料表面の状態が極めて重要な要素となっており、多くの研究者が材料表面の研究を行っている。これは、材料界面において電子のやり取りが行われるためで、材料表面の状態が非晶質、結晶質の違いがあるだけでも電解液の分解や電池の初期効率に大きく影響を与えるなどの現象がある。従って、正極材料表面が完全に炭素に覆われているか、覆われていないのかによって大きくリチウムイオン電池の物性が変化することは明らかである。特にＨＥＶ用では、表面に過大な電流が流れ、正極材料が発熱しやすいため、正極材料には、均一で体積抵抗の低いものが求められている。 In recent years, in the lithium ion battery, the state of the surface of the positive electrode material has become an extremely important factor, and many researchers have studied the surface of the material. This is because electrons are exchanged at the material interface, so even if the surface state of the material is amorphous and there is a difference in crystallinity, phenomena such as the decomposition of the electrolyte and the initial efficiency of the battery are greatly affected. is there. Therefore, it is clear that the physical properties of the lithium ion battery greatly change depending on whether the surface of the positive electrode material is completely covered with carbon or not. Particularly for HEV, since an excessive current flows on the surface and the positive electrode material easily generates heat, the positive electrode material is required to have a uniform and low volume resistance.
図１は、本発明のリチウムイオン二次電池用正極材料の一例を示す概念図である。２はリチウムイオン二次電池用正極材料である。８は凝集粒子で、ＬｉＦｅＰＯ4粒子４と、還元材の黒鉛に由来する炭素６とが入り組んで凝集粒子８を形成している。凝集粒子８の外側(凝集粒子８の表面)は、炭素層１０で被覆されている。
FIG. 1 is a conceptual diagram showing an example of a positive electrode material for a lithium ion secondary battery of the present invention. 2 is a positive electrode material for a lithium ion secondary battery. 8 is an agglomerated particle, and LiFePO 4 particle 4 and
通常、凝集粒子８内には空隙１２が散在している。この空隙１２と凝集粒子８との界面も、炭素層１０で被覆されている。
Usually, voids 12 are scattered in the aggregated particles 8. The interface between the
このリチウムイオン二次電池用正極材料２の平均粒径は１〜２０μｍで、１〜１０μｍが好ましい。黒鉛に由来する炭素６の平均粒径は０．１〜５μｍである。炭素６の含有量は３〜２０質量％である。空隙１２は５〜１５容積％である。炭素層１０の厚みは、０．０５〜１μｍで、０．１〜０．５μｍが好ましい。炭素層１０の含有量は３〜２０質量％である。
The average particle diameter of the positive electrode material 2 for a lithium ion secondary battery is 1 to 20 μm, and preferably 1 to 10 μm. The average particle diameter of
本発明のリチウムイオン二次電池用正極材料は、例えば、以下の方法により製造することができる。 The positive electrode material for a lithium ion secondary battery of the present invention can be produced, for example, by the following method.
原料の酸化鉄としては、一般式ＦｅｘＯｙ(０＜ｘ≦３、０＜ｙ≦４)で表される物質であり、Ｆｅ：Ｏ＝１：１〜２：３(モル比)が好ましく、特にＦｅＯ、Ｆｅ2Ｏ3、Ｆｅ3Ｏ4などが良い。純度は、９８質量％以上が好ましく、特に９９．５質量％以上のものが特に好ましい。純度が９８質量％未満では、不純物となる金属酸化物が多くなり、製造した本発明の正極材料を用いて電池を構成する場合、電解液中に生ずるフッ酸と反応して不導体膜を生成するため、好ましくない。 The raw material iron oxide is a substance represented by the general formula FexOy (0 <x ≦ 3, 0 <y ≦ 4), preferably Fe: O = 1: 1 to 2: 3 (molar ratio), particularly FeO, Fe 2 O 3 , Fe 3 O 4 and the like are preferable. The purity is preferably 98% by mass or more, particularly preferably 99.5% by mass or more. When the purity is less than 98% by mass, the amount of metal oxides that become impurities increases, and when a battery is formed using the produced positive electrode material of the present invention, it reacts with hydrofluoric acid generated in the electrolytic solution to form a nonconductive film. Therefore, it is not preferable.
原料の酸化鉄の平均粒子径は、還元反応を均一にするために、０．１〜１０μｍが好ましく、０．５〜２μｍが特に好ましい。酸化鉄以外の材料、例えば、シュウ酸鉄、燐酸鉄などは、還元雰囲気下では、鉄になりやすく本発明には使えない。 The average particle diameter of the raw iron oxide is preferably 0.1 to 10 μm, and particularly preferably 0.5 to 2 μm, in order to make the reduction reaction uniform. Materials other than iron oxide, such as iron oxalate and iron phosphate, tend to be iron in a reducing atmosphere and cannot be used in the present invention.
リチウム源としては、水酸化リチウム、炭酸リチウムなど一般的にＬｉＦｅＰＯ4の合成に用いられている材料で純度は９９質量％以上のものが良い。リチウム源の平均粒子径は、１〜２００μｍが好ましく、１〜５０μｍが特に好ましい。リチウム源の配合量は、元素としてのＦｅ１モルに対してＬｉ元素として０．９５〜１．０５モルが好ましい。 The lithium source is a material generally used for the synthesis of LiFePO 4 such as lithium hydroxide and lithium carbonate, and preferably has a purity of 99% by mass or more. The average particle size of the lithium source is preferably 1 to 200 μm, particularly preferably 1 to 50 μm. The blending amount of the lithium source is preferably 0.95 to 1.05 mol as Li element with respect to 1 mol of Fe as element.
燐源としては、燐酸水素アンモニウム、燐酸二水素アンモニウム、燐酸アンモニウム、酸化燐などが良く不純物が少ないものが好ましい。燐源の平均粒子径は、１〜２００μｍが好ましく、１〜５０μｍが特に好ましい。燐源の配合量は、元素としてのＦｅ１モルに対してＰ元素として０．９５〜１．０５モルが好ましい。 The phosphorus source is preferably ammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium phosphate, phosphorus oxide, or the like with low impurities. The average particle size of the phosphorus source is preferably 1 to 200 μm, particularly preferably 1 to 50 μm. The blending amount of the phosphorus source is preferably 0.95 to 1.05 mol as the P element with respect to 1 mol of Fe as the element.
酸化鉄の還元材には黒鉛を用いる。コークス、非晶質カーボン、ポリビニルアルコールやフェノール樹脂、フラン樹脂、エポキシ樹脂、セルロースなどの有機物などは還元力が不十分で、酸化鉄が十分に還元できないので好ましくなく、アスコルビン酸は、逆に還元力が強すぎるので好ましくない。 Graphite is used as a reducing material for iron oxide. Organic substances such as coke, amorphous carbon, polyvinyl alcohol, phenol resin, furan resin, epoxy resin, and cellulose are not preferable because the reducing power is insufficient and iron oxide cannot be reduced sufficiently, and ascorbic acid is reduced on the contrary. Since power is too strong, it is not preferable.
黒鉛は、酸化鉄の還元材としてばかりでなく、導電材としても作用する。この導電材としては、黒鉛以外に、石炭タール、石炭ピッチ、コークス、アセチレンブラックなどの炭素が考えられる。しかし、これらの炭素は、還元力は適度であるが、黒鉛に比べ導電率が１桁以上下がるので好ましくない。このように、酸化鉄の還元剤及び導電材として両方の性能を満足しているのは、唯一黒鉛のみである。黒鉛の添加量としては、酸化鉄の還元に１〜２質量％消費されるので、酸化鉄とリチウム源と燐源との合計量に対して３〜２０質量％が好ましい。黒鉛の平均粒子径は、１〜７０μｍが好ましく、１〜２０μｍが特に好ましい。 Graphite acts not only as a reducing material for iron oxide but also as a conductive material. As this conductive material, carbon such as coal tar, coal pitch, coke, and acetylene black can be considered in addition to graphite. However, these carbons are not preferable because their reducing power is moderate, but their electrical conductivity is lower by one digit or more than graphite. Thus, graphite is the only one that satisfies both performances as a reducing agent and conductive material for iron oxide. The amount of graphite added is preferably 1 to 2% by mass for the reduction of iron oxide, and is preferably 3 to 20% by mass with respect to the total amount of iron oxide, lithium source and phosphorus source. The average particle diameter of graphite is preferably 1 to 70 μm, particularly preferably 1 to 20 μm.
本発明においては、上記炭素質材料とともにリチウム源、酸化鉄、燐源等の原料粒子を混合して、ＬｉＦｅＰＯ4粒子及び炭素で形成された凝集粒子を合成するための混合物を作製する。混合方式としては乾式、湿式混合で行うことが好ましい。遊星ミル、振動ミル、ボールミル、ヘンシェルミキサー、アトライター等の汎用混合機を用いて１〜５時間混合することが好ましい。 In the present invention, raw material particles such as a lithium source, iron oxide, and phosphorus source are mixed together with the carbonaceous material to prepare a mixture for synthesizing LiFePO 4 particles and aggregated particles formed of carbon. The mixing method is preferably dry or wet mixing. It is preferable to mix for 1 to 5 hours using a general-purpose mixer such as a planetary mill, vibration mill, ball mill, Henschel mixer, or attritor.
この原料粒子の混合工程で、粉砕、混合、造粒が同時に起こる。後工程の流動床処理にとって混合物の粒度が大きくなりすぎる場合は、得られた混合物を、分級、篩分け、篩上分の解砕などを行い、最大粒子径を２０μｍ以下に調節することが好ましい。 In this raw material particle mixing step, pulverization, mixing, and granulation occur simultaneously. When the particle size of the mixture becomes too large for the subsequent fluidized bed treatment, the obtained mixture is preferably classified, sieved, and crushed on the sieve to adjust the maximum particle size to 20 μm or less. .
得られた混合物は、不活性ガス中で６００〜９００℃で焼成する。これにより、ＬｉＦｅＰＯ4粒子及び炭素で形成された凝集粒子を合成できる。この凝集粒子は正極に組込まれ、正極活物質となる。不活性ガスとしては、アルゴン、窒素等で問題なく、実用的には窒素で十分である。焼成温度は、より好ましくは６００〜８００℃である。焼成時間は１〜５時間が好ましい。焼成に用いる反応装置としては、流動床及び固定床反応装置のいずれのものを用いても行うことができるが、粉体に対する熱伝導が均一な流動床の方が品質的に優れたものが得られる。 The obtained mixture is fired at 600 to 900 ° C. in an inert gas. This allows synthesizing aggregated particles formed by LiFePO 4 particles and carbon. The aggregated particles are incorporated into the positive electrode and become a positive electrode active material. As the inert gas, there is no problem with argon, nitrogen or the like, and nitrogen is sufficient for practical use. The firing temperature is more preferably 600 to 800 ° C. The firing time is preferably 1 to 5 hours. As the reaction apparatus used for the calcination, either a fluidized bed or a fixed bed reaction apparatus can be used. However, a fluidized bed with uniform heat conduction with respect to the powder is superior in quality. It is done.
上記焼成によって製造された凝集粒子は、次いでその外表面に炭素層が形成される。炭素層の形成は熱ＣＶＤ処理により行う。 The aggregated particles produced by the firing are then formed with a carbon layer on the outer surface. The carbon layer is formed by a thermal CVD process.
熱ＣＶＤ反応は、粉体を混合しながらＣＶＤ処理可能な流動床炉で行うことが好ましい。固定床反応装置は、ガスが材料表面を流れ易いので、凝集粒子の堆積された位置により炭素の沈着量が不均一となるので使用することができない。流動床炉を用いる場合は、焼成反応、熱ＣＶＤ反応を続けて行うことができるので設備的なコストメリットが大きい。 The thermal CVD reaction is preferably performed in a fluidized bed furnace capable of performing a CVD process while mixing powder. The fixed bed reactor cannot be used because the gas tends to flow on the surface of the material, and the deposited amount of carbon becomes uneven depending on the position where the aggregated particles are deposited. In the case of using a fluidized bed furnace, since the firing reaction and the thermal CVD reaction can be carried out continuously, the cost advantage of equipment is great.
熱ＣＶＤ用炭素源は、有機溶剤、例えば、ベンゼン、トルエンなどの芳香族系の炭化水素化合物やガス状のメタンやエチレン、アセチレンなどの脂肪族系炭化水素化合物を用いることができる。芳香族系の炭化水素化合物を用いる場合、結晶性の高い炭素層で被覆された複合粒子が得られ、導電性が高くなるためより好ましい。ＣＶＤ反応温度は、７００〜９５０℃が好ましく、８００〜９００℃が特に好ましい。反応時間は０．５〜３時間が好ましい。 As the carbon source for thermal CVD, an organic solvent, for example, an aromatic hydrocarbon compound such as benzene or toluene, or an aliphatic hydrocarbon compound such as gaseous methane, ethylene, or acetylene can be used. In the case of using an aromatic hydrocarbon compound, composite particles coated with a carbon layer having high crystallinity are obtained, which is more preferable because conductivity is increased. The CVD reaction temperature is preferably 700 to 950 ° C, particularly preferably 800 to 900 ° C. The reaction time is preferably 0.5 to 3 hours.
熱ＣＶＤ法以外の方法として石炭タールなどを予め原料中に混合し、固定床で焼成し、石炭タール中の揮発分によって材料をＣＶＤ処理する方法が提案されているが、この方法においてもガスの流れを均一に制御することは難しく、１粒子単位での炭素被覆が不完全になり、各粒子間での炭素量のばらつきも大きくなる。 As a method other than the thermal CVD method, coal tar or the like is previously mixed in the raw material, fired in a fixed bed, and a material is CVD-treated by the volatile matter in the coal tar. It is difficult to control the flow uniformly, and the carbon coating for each particle becomes incomplete, and the variation in the amount of carbon among the particles also increases.
これは、石炭タール中の揮発ガスの流れが、不均一であるとともにＬｉＦｅＰＯ4粒子そのものの移動がないことに起因しており、固定床炉では避けることができない問題である。加えて、揮発ガスの流れの良いところでは、粒子間での融着がおこるため、後処理の解砕や分級時に融着部分が剥離し、ＬｉＦｅＰＯ4粒子表面が露出する。以上にように凝集粒子表面に均一に炭素層を形成するには凝集粒子を混ぜながら、炭素源ガスを高温で接触させることが好ましく、この観点から流動床を用いる熱ＣＶＤ法は最適である。 This is because the flow of volatile gas in the coal tar is not uniform and the LiFePO 4 particles themselves do not move, which is a problem that cannot be avoided in a fixed bed furnace. In addition, since fusion between particles occurs where the flow of volatile gas is good, the fusion part is peeled off during disintegration and classification in post-processing, and the surface of LiFePO 4 particles is exposed. As described above, in order to uniformly form a carbon layer on the surface of the aggregated particles, it is preferable to contact the carbon source gas at a high temperature while mixing the aggregated particles. From this viewpoint, the thermal CVD method using a fluidized bed is optimal.
石炭タールや有機溶剤を除く有機物を炭素化して得られる炭素層は、一般的に非晶質であるために、導電性が低くなる傾向があるが、本発明による熱ＣＶＤ法で形成される炭素層は結晶質になりやすく、導電性が非晶質のものより高くなる。凝集粒子を被覆する炭素層の違いを明らかにする方法としてラマン分析が好ましい。ラマン分析は、測定対象の表面の情報が得られるので、製造した正極材料を繰り返し測定することにより、正極材料の表面がどの程度完全に炭素層で被覆されているかに関する情報と被覆炭素層が非晶質、結晶質のどちらであるかを判定できる。 Carbon layers obtained by carbonizing organic substances other than coal tar and organic solvents are generally amorphous and therefore tend to have low conductivity, but carbon formed by the thermal CVD method according to the present invention. Layers tend to be crystalline and are more conductive than amorphous. Raman analysis is preferable as a method for clarifying the difference in the carbon layer covering the aggregated particles. In Raman analysis, information on the surface of the measurement target is obtained. By repeatedly measuring the manufactured positive electrode material, information on how completely the surface of the positive electrode material is covered with the carbon layer and the non-covered carbon layer are not present. Whether it is crystalline or crystalline can be determined.
被覆炭素が結晶質とは、例えば特開２００１−２０２９６１号公報に開示されているように、被覆炭素のＸ線回折で求められる平均面間隔ｄ002が０．３３７ｎｍ未満のものである。 And coating carbon crystalline, for example, as disclosed in JP 2001-202961, the average spacing d 002 obtained by X-ray diffraction of the carbon coating is of less than 0.337 nm.
本発明の正極材料と上記石炭タールで炭素層を形成した正極材料との表面状態をラマン分析で比較すると、本発明の正極材料は、ラマン分光法で１５８０ｃｍ-1のピーク強度Ｇに対する１３６０ｃｍ-1のピーク強度Ｃの比(Ｃ／Ｇ)が０．５以下であり、且つ１５８０ｃｍ-1のピーク強度Ｇに対する９００〜１２００ｃｍ-1のピーク強度Ｆの比(Ｆ／Ｇ)が０．１以下である。 When the surface state of the positive electrode material in the positive electrode material and the coal tar to form a carbon layer of the present invention are compared with Raman analysis, the positive electrode material of the present invention, 1360 cm -1 to the peak intensity G of 1580 cm -1 in Raman spectroscopy of and the ratio of the peak intensity C (C / G) is 0.5 or less, and the ratio of the peak intensity F of 900～1200Cm -1 to the peak intensity G of 1580 cm -1 (F / G) is 0.1 or less is there.
(Ｆ／Ｇ)が０．１以下であることは、ＬｉＦｅＰＯ4由来の９００〜１２００ｃｍ-1のピーク強度がほとんどないことを意味しており、本正極材料表面が炭素層で完全に被覆されていることを示している。また、(Ｃ／Ｇ)が０．５以下であることは、被覆炭素層が黒鉛層に近い結晶性の高い炭素層であることを示している。 That (F / G) is 0.1 or less means that there is almost no peak intensity of 900 to 1200 cm −1 derived from LiFePO 4 , and the surface of this positive electrode material is completely covered with a carbon layer. It shows that. Further, (C / G) being 0.5 or less indicates that the coated carbon layer is a carbon layer having high crystallinity close to that of the graphite layer.
一方、石炭タールで被覆した正極材料は、１５８０ｃｍ-1のピーク強度Ｇに対する１３６０ｃｍ-1のピーク強度Ｃの比(Ｃ／Ｇ)が０．５以上であり、且つ１５８０ ｃｍ-1のピーク強度Ｇに対する９００〜１２００ｃｍ-1のピーク強度Ｆの比(Ｆ／Ｇ)が０．５以上であるため、ＬｉＦｅＰＯ4が炭素層で部分的にしか被覆されていない。しかも被覆されている炭素層は、非晶質炭素に近い性状を示す。 On the other hand, a positive electrode material coated with coal tar is a ratio of the peak intensity C of 1360 cm -1 to the peak intensity G of 1580 cm -1 (C / G) is 0.5 or more and 1580 peak intensity of cm -1 G Since the ratio (F / G) of the peak intensity F of 900 to 1200 cm −1 with respect to is 0.5 or more, LiFePO 4 is only partially covered with the carbon layer. Moreover, the coated carbon layer exhibits properties close to amorphous carbon.
本発明材料を正極材料として、リチウムイオン二次電池用正極を調製する方法を以下に示すが、特に限定されるものではない。 A method for preparing a positive electrode for a lithium ion secondary battery using the material of the present invention as a positive electrode material is shown below, but is not particularly limited.
本正極材料にバインダー(例えば、ＰＶＤＦ：ポリビニリデンフルオライド)を溶解した溶剤(例えば、１−メチル−２−ピロリドン)を加え、充分に混練しスラリー状にする。このスラリーをアルミ箔からなる集電体にドクターブレード等を用いて２０〜１００μｍの厚みにコーティングする。これを乾燥しロールプレス等により加圧して電極を作製する。 A solvent (for example, 1-methyl-2-pyrrolidone) in which a binder (for example, PVDF: polyvinylidene fluoride) is dissolved is added to the positive electrode material, and the mixture is sufficiently kneaded to form a slurry. The slurry is coated on a current collector made of aluminum foil to a thickness of 20 to 100 μm using a doctor blade or the like. This is dried and pressed by a roll press or the like to produce an electrode.
負極材料は、金属リチウム、黒鉛及び黒鉛類似炭素材料、コークス、リチウムと合金可能な酸化物、金属及びその炭素との複合体等の公知の負極材料を用いることができる。これら負極材料はバインダーを溶解した溶剤と十分に混練後、集電体に塗布し成型して調製できる。また、セパレーターについても特に限定はなく、ポリプロピレンやポリエチレン等の公知の材料を用いることができる。 As the negative electrode material, known negative electrode materials such as metallic lithium, graphite and graphite-like carbon materials, coke, oxides capable of being alloyed with lithium, composites of metals and carbon thereof, and the like can be used. These negative electrode materials can be prepared by sufficiently kneading with a solvent in which a binder is dissolved, and then applying and molding the current collector. The separator is not particularly limited, and a known material such as polypropylene or polyethylene can be used.
電解液の主溶媒である非水系溶媒としては、リチウム塩を溶解する非プロトン性低誘電率の公知の溶媒を用いることができる。例えば、エチレンカーボネート、ジメチルカーボネート、メチルエチルカーボネート、プロピレンカーボネート、ジエチレンカーボネート、アセトニトリル、プロピオニトリル、テトラヒドロフラン、γ−ブチロラクトン等の溶媒を単独で、又は２種類以上の溶媒を混合して用いることができる。 As the non-aqueous solvent that is the main solvent of the electrolytic solution, a known aprotic low dielectric constant solvent that dissolves the lithium salt can be used. For example, solvents such as ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, propylene carbonate, diethylene carbonate, acetonitrile, propionitrile, tetrahydrofuran, and γ-butyrolactone can be used alone or in admixture of two or more kinds. .
電解質として用いられるリチウム塩としてはＬｉＣｌＯ、ＬｉＡｓＦ6、ＬｉＰＦ6、ＬｉＢＦ4、ＬｉＢ(Ｃ6Ｈ5)4、ＬｉＣｌ、ＬｉＢｒ、ＣＨ3ＳＯ3Ｌｉ等を例示できこれらの塩を単独、又は２種類以上を混合して用いることができる。 Examples of the lithium salt used as the electrolyte include LiClO, LiAsF 6 , LiPF 6 , LiBF 4 , LiB (C 6 H 5 ) 4 , LiCl, LiBr, CH 3 SO 3 Li, etc., and these salts can be used alone or in two types The above can be mixed and used.
以上の材料を使用して、アルゴン雰囲気でコイン電池を作製し、電気化学的な充放電量を測定することにより、正極材料の評価が可能である。 The positive electrode material can be evaluated by producing a coin battery in an argon atmosphere using the above materials and measuring the electrochemical charge / discharge amount.
以下、本発明を実施例及び比較例により更に具体的に説明する。また、これら実施例及び比較例における負極材の各物性値は以下の方法で測定した。 Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. Moreover, each physical property value of the negative electrode material in these Examples and Comparative Examples was measured by the following methods.
各物性は、以下の装置、手順で実施した。 Each physical property was implemented with the following apparatuses and procedures.
［ラマン分析］
ラマン分光装置は、JOVAN-YVON-SPEX製、分光器は５００Ｍ、検出器はSpectrum One CCD検出器、Argon ion レーザー装備していた。レーザーの発振線は５１４５Ａ、出力は５０ｍＷであった。得られたチャートより、ベースライン補正をし、９００〜１２００ｃｍ-1(Ｆ)、１３６０ｃｍ-1(Ｃ)、１５８０ｃｍ-1(Ｇ)の各ピーク強度を算出し、ピーク強度比Ｃ／Ｇ、Ｆ／Ｇを求めた。同様の測定を５回繰り返し、各ピーク強度比の平均値を求め、測定材料のピーク強度比とした。
[Raman analysis]
The Raman spectrometer was manufactured by JOVAN-YVON-SPEX, the spectrometer was equipped with 500M, the detector was equipped with a Spectrum One CCD detector, and an Argon ion laser. The laser oscillation line was 5145 A, and the output was 50 mW. Baseline correction is performed from the obtained chart, and peak intensities of 900 to 1200 cm −1 (F), 1360 cm −1 (C), and 1580 cm −1 (G) are calculated, and peak intensity ratios C / G, F / G was determined. The same measurement was repeated 5 times, the average value of each peak intensity ratio was calculated | required, and it was set as the peak intensity ratio of a measurement material.
［平均粒子径及び粒度分布］
島津製作所(株)製レーザー式回折粒度分布測定装置ＳＡＬＤ−１０００で測定した。
[Average particle size and particle size distribution]
This was measured with a laser diffraction particle size distribution analyzer SALD-1000 manufactured by Shimadzu Corporation.
［全炭素含有量］
ＪＩＳ Ｍ ８８１３ シェフィールド高温法により測定した。
[Total carbon content]
Measured by JIS M 8813 Sheffield high temperature method.
［炭素被覆量］
ＪＩＳ Ｍ ８８１３により測定した。
[Carbon coverage]
It was measured according to JIS M 8813.
［比表面積］
日本ベル製ベルソープ２８で測定し、ＢＥＴ法により算出した。
[Specific surface area]
Measured with a
［タップ密度］
１０ｍＬのガラス製メスシリンダーに試料を入れてタッピングし、試料の容積が変化しなくなったことを確認した後、試料容積を測定した。試料質量を試料容積で除した値をタップ密度とした。
[Tap density]
The sample was put into a 10 mL glass graduated cylinder and tapped, and after confirming that the volume of the sample did not change, the sample volume was measured. The value obtained by dividing the sample mass by the sample volume was defined as the tap density.
［ＸＲＤ法による結晶解析］
Ｐｈｉｌｉｐｓ社製Ｘ線回折装置 Ｘ‘ｐｅｒｔ ｐｒｏ(商品名)で測定した。
[Crystal analysis by XRD method]
Measurement was performed with an X-ray diffractometer X'pert pro (trade name) manufactured by Philips.
［実施例１］
四酸化三鉄(和光社製試薬１級Ｆｅ3Ｏ4)１モル(７７ｇ)、燐酸二水素アンモニウム(和光社製試薬特級)１モル(１１５ｇ)と炭酸リチウム(和光社製試薬特級)１モル(３７ｇ)、黒鉛１２ｇ(酸化鉄とリチウム源と燐源との合計量に対して５質量％)を計量し、ボールミルで４ｈｒ混合した。得られた混合物を篩分けして得た粒度２０μｍ以下のものを管状炉に充填して窒素雰囲気下、８００℃で１ｈｒ焼成し凝集粒子を得た。この凝集粒子をＣＶＤ処理した。凝集粒子２０５ｇを流動層式炉に仕込み、窒素雰囲気下、昇温速度１０℃／ｍｉｎで室温から８００℃まで昇温した。昇温後、以下の条件でＣＶＤ処理を実施した。
[Example 1]
1 mol (77 g) of triiron tetroxide (
ＣＶＤ処理では、炭素源としてのトルエンを０．５ｍｌ／ｍｉｎで１ｈｒ流動層反応炉に供給した。ＣＶＤ処理後、炉内を冷却し、炭素層で被覆された粒度２０μｍ以下の正極材料を炉から取出した。この正極材料を物性試験及び電極試験に供した。得られた正極材料をＸ線回折装置(ＸＲＤ)で測定するとＬｉＦｅＰＯ4と同定された。 In the CVD treatment, toluene as a carbon source was supplied to the 1 hr fluidized bed reactor at 0.5 ml / min. After the CVD treatment, the inside of the furnace was cooled, and the positive electrode material with a particle size of 20 μm or less coated with the carbon layer was taken out from the furnace. This positive electrode material was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured with an X-ray diffractometer (XRD), it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度７μｍ、全炭素含有量８質量％、炭素被覆量３質量％、比表面積１４ｍ2／ｇ、タップ密度１．３９ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．２であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 7 μm, a total carbon content of 8% by mass, a carbon coating amount of 3% by mass, a specific surface area of 14 m 2 / g, a tap density of 1.39 g / cm 3 , and a peak intensity by Raman spectroscopy. The ratio (C / G) was 0.2, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
本例の材料の電極評価を以下のように実施した。得られた正極材料９３質量％にＰＶＤＦを７質量％配合し、全量を４ｇとした。スラリー濃度は、５０質量％になるように２メチルピロリドンで調整し、これを遠心混合機で５ｍｉｎ混合し、混合後コーターを用いて厚さ５０μｍの電極を作製し、乾燥した。 The electrode evaluation of the material of this example was performed as follows. 7 mass% of PVDF was mix | blended with 93 mass% of obtained positive electrode materials, and the whole quantity was set to 4 g. The slurry concentration was adjusted with 2 methylpyrrolidone so as to be 50% by mass, mixed for 5 min with a centrifugal mixer, and after mixing, an electrode having a thickness of 50 μm was prepared using a coater and dried.
乾燥後、２ｍｍΦに切り出し７．３ＭＰａ(４００ｋｇ/ｃｍ2)でプレスした。プレス後、乾燥してアルゴン雰囲気下でＣ２０３２セル電池を作製した。 After drying, it was cut into 2 mmφ and pressed at 7.3 MPa (400 kg / cm 2 ). After pressing, it was dried and a C2032 cell battery was produced under an argon atmosphere.
このセル電池は、正極に本例の材料を、負極にリチウム金属を、セパレーターにポリプロピレン膜を用い、電解液ＬｉＰＦ6 １ｍｏｌ／Ｌ；ＥＣ：ＤＭＣ＝１：２ｖｏｌ％(富山化学製)を０．２３ｍｏｌの条件で使用して作製した。このセル電池について、０．１ｍＡ／ｃｍ2、３〜４Ｖ、２５℃で、ナガノ製充放電装置２００５ｗで初期特性を求めた。
In this cell battery, the material of this example is used for the positive electrode, the lithium metal is used for the negative electrode, and the polypropylene film is used for the separator, and the
高出力性能の測定は、対極をカーボン電極として充電条件 ５０ｍＡ／ｃｍ2、１２ｓｅｃ、放電条件 ２５ｍＡ／ｃｍ2、２４ｓｅｃの条件で実施した。 The high output performance was measured under the conditions of charging conditions of 50 mA / cm 2 and 12 sec and discharging conditions of 25 mA / cm 2 and 24 sec using the counter electrode as a carbon electrode.
以上の電池評価結果を表―２にまとめた。 The above battery evaluation results are summarized in Table 2.
［実施例２］
ＣＶＤ処理の炭素源として、メタンを使用した以外は実施例１と同様に操作して、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 2]
A positive electrode material with a particle size of 20 μm or less coated with a carbon layer was obtained in the same manner as in Example 1 except that methane was used as the carbon source for the CVD treatment, and this was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度９μｍ、全炭素含有量９質量％、炭素被覆量４質量％、比表面積１７ｍ2／ｇ、タップ密度１．３７ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．４であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 9 μm, a total carbon content of 9% by mass, a carbon coating amount of 4% by mass, a specific surface area of 17 m 2 / g, a tap density of 1.37 g / cm 3 , and a peak intensity by Raman spectroscopic analysis. The ratio (C / G) was 0.4, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例３］
凝集粒子製造時の原料配合において四酸化三鉄(和光社製試薬１級Ｆｅ3Ｏ4)の代わりに酸化第一鉄(和光社製試薬１級ＦｅＯ)１モル(７２ｇ)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 3]
Except that 1 mol (72 g) of ferrous oxide (reagent primary FeO manufactured by Wako) was weighed in place of triiron tetroxide (reagent primary Fe 3 O 4 manufactured by Wako) in the raw material formulation during the production of the aggregated particles. A mixing process was performed under the same blending conditions as in Example 1, then a sieving process and a firing process in a tubular furnace were performed under the same conditions as in Example 1. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度７μｍ、全炭素含有量８質量％、炭素被覆量３質量％、比表面積６ｍ2／ｇ、タップ密度１．４４ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．３であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 7 μm, a total carbon content of 8% by mass, a carbon coating amount of 3% by mass, a specific surface area of 6 m 2 / g, a tap density of 1.44 g / cm 3 , and a peak intensity by Raman spectroscopic analysis. The ratio (C / G) was 0.3, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例４］
凝集粒子製造時の原料配合において四酸化三鉄(和光社製試薬１級Ｆｅ3Ｏ4)の代わりに酸化第二鉄(和光社製試薬１級Ｆｅ2Ｏ3)１モル(８０ｇ)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 4]
1 mol (80 g) of ferric oxide (Wako Co.,
この正極材料の物性は、平均粒度６μｍ、全炭素含有量８質量％、炭素被覆量４質量％、比表面積８ｍ2／ｇ、タップ密度１．３５ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．３であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 6 μm, a total carbon content of 8 mass%, a carbon coating amount of 4 mass%, a specific surface area of 8 m 2 / g, a tap density of 1.35 g / cm 3 , and a peak intensity by Raman spectroscopy. The ratio (C / G) was 0.3, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例５］
凝集粒子製造時の原料配合において黒鉛２３ｇ(酸化鉄とリチウム源と燐源との合計量に対して１０質量％)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 5]
Mixing treatment was performed under the same mixing conditions as in Example 1 except that 23 g of graphite (10% by mass with respect to the total amount of iron oxide, lithium source, and phosphorus source) was weighed in the raw material mixture during the production of the aggregated particles. The sieving process was performed under the same conditions as in No. 1, and the baking process was performed in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度１０μｍ、全炭素含有量１３質量％、炭素被覆量４質量％、比表面積９ｍ2／ｇ、タップ密度１．３１ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．２であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 10 μm, a total carbon content of 13% by mass, a carbon coating amount of 4% by mass, a specific surface area of 9 m 2 / g, a tap density of 1.31 g / cm 3 , and a peak intensity by Raman spectroscopy. The ratio (C / G) was 0.2, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例６］
凝集粒子製造時の原料配合において黒鉛３４ｇ(酸化鉄とリチウム源と燐源との合計量に対して１５質量％)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 6]
Mixing treatment was performed under the same mixing conditions as in Example 1, except that 34 g of graphite (15% by mass with respect to the total amount of iron oxide, lithium source, and phosphorus source) was weighed in the raw material mixture during the production of aggregated particles. The sieving process was performed under the same conditions as in No. 1, and the baking process was performed in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度１２μｍ、全炭素含有量１８質量％、炭素被覆量４質量％、比表面積６ｍ2／ｇ、タップ密度１．２５ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．２であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 12 μm, a total carbon content of 18% by mass, a carbon coating amount of 4% by mass, a specific surface area of 6 m 2 / g, a tap density of 1.25 g / cm 3 , and a peak intensity by Raman spectroscopy. The ratio (C / G) was 0.2, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例７］
凝集粒子製造時の原料配合において燐酸二水素アンモニウム(和光社製試薬特級)０．９５モル(１０９ｇ)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 7]
The mixing conditions were the same as in Example 1, except that 0.95 mol (109 g) of ammonium dihydrogen phosphate (special grade reagent manufactured by Wako Co., Ltd.) was weighed in the raw material mixture during the production of the aggregated particles. Sieving treatment and firing treatment in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度７μｍ、全炭素含有量８質量％、炭素被覆量４質量％、比表面積７ｍ2／ｇ、タップ密度１．３８ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．３であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 7 μm, a total carbon content of 8% by mass, a carbon coating amount of 4% by mass, a specific surface area of 7 m 2 / g, a tap density of 1.38 g / cm 3 , and a peak intensity by Raman spectroscopic analysis. The ratio (C / G) was 0.3, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例８］
凝集粒子製造時の原料配合において燐酸二水素アンモニウム(和光社製試薬特級)１．０５モル(１２０ｇ)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 8]
Mixing treatment was carried out under the same mixing conditions as in Example 1 except that 1.05 mol (120 g) of ammonium dihydrogen phosphate (special grade reagent manufactured by Wako Co., Ltd.) was weighed in the raw material mixture at the time of production of the aggregated particles. Sieving treatment and firing treatment in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度８μｍ、全炭素含有量８質量％、炭素被覆量４質量％、比表面積７ｍ2／ｇ、タップ密度１．３８ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．３であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 8 μm, a total carbon content of 8 mass%, a carbon coating amount of 4 mass%, a specific surface area of 7 m 2 / g, a tap density of 1.38 g / cm 3 , and a peak intensity by Raman spectroscopy. The ratio (C / G) was 0.3, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例９］
凝集粒子製造時の原料配合において炭酸リチウム(和光社製試薬特級)０．９５モル(３５ｇ)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 9]
Except that 0.95 mol (35 g) of lithium carbonate (special grade reagent manufactured by Wako Co., Ltd.) was weighed in the raw material mixture at the time of the production of the aggregated particles, mixing treatment was performed under the same mixing conditions as in Example 1, and then sieved under the same conditions as in Example 1. Divided and fired in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度７μｍ、全炭素含有量８質量％、炭素被覆量４質量％、比表面積８ｍ2／ｇ、タップ密度１．３９ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．３であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 7 μm, a total carbon content of 8% by mass, a carbon coating amount of 4% by mass, a specific surface area of 8 m 2 / g, a tap density of 1.39 g / cm 3 , and a peak intensity by Raman spectroscopic analysis. The ratio (C / G) was 0.3, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［実施例１０］
凝集粒子製造時の原料配合において炭酸リチウム(和光社製試薬特級)１．０５モル(３９ｇ)を計量した以外は実施例１と同様の配合条件で混合処理、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理し、炭素層で被覆された粒度２０μｍ以下の正極材料を得、これを物性試験及び電極試験に供した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。
[Example 10]
Except that 1.05 mol (39 g) of lithium carbonate (special grade reagent manufactured by Wako Co., Ltd.) was weighed in the raw material mixture at the time of the production of the aggregated particles, mixing treatment was performed under the same mixing conditions as in Example 1, and then sieved under the same conditions as in Example 1. Divided and fired in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1 to obtain a positive electrode material with a particle size of 20 μm or less coated with a carbon layer, which was subjected to a physical property test and an electrode test. When the obtained positive electrode material was measured by XRD, it was identified as LiFePO 4 .
この正極材料の物性は、平均粒度７μｍ、全炭素含有量８質量％、炭素被覆量４質量％、比表面積８ｍ2／ｇ、タップ密度１．３７ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．３であり、ピーク強度比(Ｆ／Ｇ)が０．０５以下であった。粉体物性を表―１にまとめた。 The physical properties of this positive electrode material are an average particle size of 7 μm, a total carbon content of 8% by mass, a carbon coating amount of 4% by mass, a specific surface area of 8 m 2 / g, a tap density of 1.37 g / cm 3 , and a peak intensity by Raman spectroscopy. The ratio (C / G) was 0.3, and the peak intensity ratio (F / G) was 0.05 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［比較例１］
酸化鉄の代わりにシュウ酸鉄１８０ｇ使用して実施例１と同様の配合条件で混合処理し、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理した。得られた材料をＸＲＤで測定するとＬｉＦｅＰＯ4８１質量％、Ｆｅ3Ｏ4１３質量％、Ｆｅ６質量％の混合物と同定された。この混合物の物性は、平均粒度２２μｍ、全炭素含有量７質量％、炭素被覆量２質量％、比表面積２９ｍ2／ｇ、タップ密度１．４３ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．１であり、ピーク強度比(Ｆ／Ｇ)が０．１以下であった。粉体物性を表―１にまとめた。
[Comparative Example 1]
180 g of iron oxalate was used instead of iron oxide and mixed under the same blending conditions as in Example 1, followed by sieving under the same conditions as in Example 1 and firing in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1. Measurement of the material obtained in XRD LiFePO 4 81 wt%, Fe 3 O 4 13 wt%, was identified as a mixture of Fe6 mass%. The physical properties of this mixture were an average particle size of 22 μm, a total carbon content of 7% by mass, a carbon coating amount of 2% by mass, a specific surface area of 29 m 2 / g, a tap density of 1.43 g / cm 3 , and a peak intensity ratio by Raman spectroscopy. (C / G) was 0.1, and the peak intensity ratio (F / G) was 0.1 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［比較例２］
黒鉛の代わりにアセチレンブラックを１２ｇ使用して実施例１と同様の配合条件で混合処理し、次いで実施例１と同条件で篩分け処理、管状炉での焼成処理をした。その処理物を流動層式炉に仕込み、実施例１と同条件でＣＶＤ処理した。得られた正極材料をＸＲＤで測定するとＬｉＦｅＰＯ4９２質量％とＦｅ3Ｏ4８質量％の混合物と同定された。この混合物の物性は、平均粒度１７μｍ、全炭素含有量９質量％、炭素被覆量４質量％、比表面積１９ｍ2／ｇ、タップ密度１．３３ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が０．１であり、ピーク強度比(Ｆ／Ｇ)が０．１以下であった。粉体物性を表―１にまとめた。
[Comparative Example 2]
12 g of acetylene black was used instead of graphite and mixed under the same blending conditions as in Example 1, followed by sieving under the same conditions as in Example 1 and firing in a tubular furnace. The treated product was charged into a fluidized bed furnace and subjected to CVD treatment under the same conditions as in Example 1. When the obtained positive electrode material was measured by XRD, it was identified as a mixture of 92% by mass of LiFePO 4 and 8% by mass of Fe 3 O 4 . The physical properties of this mixture are an average particle size of 17 μm, a total carbon content of 9% by mass, a carbon coating amount of 4% by mass, a specific surface area of 19 m 2 / g, a tap density of 1.33 g / cm 3 , and a peak intensity ratio by Raman spectroscopy. (C / G) was 0.1, and the peak intensity ratio (F / G) was 0.1 or less. The powder properties are summarized in Table-1.
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。 A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
［比較例３］
実施例１と同様の配合条件で混合処理した試料をＣＶＤ処理する代わりに石炭タールを１５質量％原料中に混ぜて、固定床炉で焼成した。得られた材料をＸＲＤで測定するとＬｉＦｅＰＯ4と同定された。この炭素とＬｉＦｅＰＯ4複合体からなる正極材料の物性は、平均粒度８μｍ、全炭素含有量１３質量％、炭素被覆量８質量％、比表面積２６ｍ2／ｇ、タップ密度１．３５ｇ／ｃｍ3であり、ラマン分光分析によるピーク強度比(Ｃ／Ｇ)が１．０であり、ピーク強度比(Ｆ／Ｇ)が２．０以上であった。粉体物性を表―１にまとめた。
[Comparative Example 3]
Instead of subjecting the sample mixed and processed under the same blending conditions as in Example 1 to CVD treatment, coal tar was mixed into 15% by mass raw material and fired in a fixed bed furnace. When the obtained material was measured by XRD, it was identified as LiFePO 4 . The physical properties of the positive electrode material composed of this carbon and LiFePO 4 composite are as follows: average particle size 8 μm,
実施例１と同様に電池を作製し、その電池評価結果を表―２にまとめた。
A battery was produced in the same manner as in Example 1, and the battery evaluation results are summarized in Table 2.
２ リチウムイオン二次電池用正極材料
４ ＬｉＦｅＰＯ4粒子
６ 還元材の黒鉛に由来する炭素
８ 凝集粒子
１０ 凝集粒子の表面を被覆した炭素層
１２ 空隙
2 Positive electrode material for lithium ion secondary battery 4 LiFePO 4 particles 6 Carbon derived from graphite as a reducing material 8
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107534145A (en) * | 2015-05-01 | 2018-01-02 | 艾利电力能源有限公司 | Positive electrode active material for nonaqueous electrolyte secondary battery, positive pole and secondary cell |
Families Citing this family (53)
| Publication number | Priority date | Publication date | Assignee | Title |
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| JP6064143B2 (en) * | 2014-09-10 | 2017-01-25 | 太平洋セメント株式会社 | Positive electrode material for lithium ion secondary battery |
| CN107615532B (en) * | 2015-05-14 | 2020-07-31 | 株式会社村田制作所 | Nonaqueous electrolyte secondary battery |
| JP2018055886A (en) * | 2016-09-27 | 2018-04-05 | 株式会社Ｇｓユアサ | Carbon-coated positive electrode active material, method for manufacturing the same, positive electrode, and nonaqueous electrolyte power storage device |
| JP7087889B2 (en) * | 2018-09-27 | 2022-06-21 | 株式会社豊田自動織機 | Composite particles |
| JP7131258B2 (en) * | 2018-09-27 | 2022-09-06 | 株式会社豊田自動織機 | Composite particle manufacturing method |
| WO2020256115A1 (en) * | 2019-06-19 | 2020-12-24 | Ｔｐｒ株式会社 | Current collector for power storage device electrode, manufacturing method thereof, and power storage device |
| JP6947259B1 (en) * | 2020-08-20 | 2021-10-13 | 住友大阪セメント株式会社 | Positive electrode material for alkali metal ion batteries, positive electrode and alkali metal ion batteries |
| KR102553635B1 (en) * | 2022-09-27 | 2023-07-10 | 주식회사 케이켐비즈 | Positive electrode active material, positive electrode and secondary battery comprising the same |
| WO2024197861A1 (en) | 2023-03-31 | 2024-10-03 | 昆明理工大学 | Battery positive electrode material and treatment method therefor, and battery |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002075364A (en) * | 2000-08-30 | 2002-03-15 | Sony Corp | Positive electrode active material, its manufacturing method, nonaqueous electrolyte battery, and manufacturing method of battery |
-
2005
- 2005-04-20 JP JP2005122988A patent/JP4684727B2/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002075364A (en) * | 2000-08-30 | 2002-03-15 | Sony Corp | Positive electrode active material, its manufacturing method, nonaqueous electrolyte battery, and manufacturing method of battery |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107534145A (en) * | 2015-05-01 | 2018-01-02 | 艾利电力能源有限公司 | Positive electrode active material for nonaqueous electrolyte secondary battery, positive pole and secondary cell |
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