JP3483099B2 - Method for producing lithium hexafluorophosphate - Google Patents
Method for producing lithium hexafluorophosphateInfo
- Publication number
- JP3483099B2 JP3483099B2 JP07982797A JP7982797A JP3483099B2 JP 3483099 B2 JP3483099 B2 JP 3483099B2 JP 07982797 A JP07982797 A JP 07982797A JP 7982797 A JP7982797 A JP 7982797A JP 3483099 B2 JP3483099 B2 JP 3483099B2
- Authority
- JP
- Japan
- Prior art keywords
- lithium hexafluorophosphate
- dimethyl carbonate
- lithium
- solvent
- crystal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- -1 lithium hexafluorophosphate Chemical compound 0.000 title claims description 51
- 238000004519 manufacturing process Methods 0.000 title claims description 16
- 239000013078 crystal Substances 0.000 claims description 43
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 claims description 34
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 claims description 25
- 238000006243 chemical reaction Methods 0.000 claims description 21
- OBCUTHMOOONNBS-UHFFFAOYSA-N phosphorus pentafluoride Chemical compound FP(F)(F)(F)F OBCUTHMOOONNBS-UHFFFAOYSA-N 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 238000001953 recrystallisation Methods 0.000 claims description 3
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims 1
- 229910001947 lithium oxide Inorganic materials 0.000 claims 1
- 239000002904 solvent Substances 0.000 description 24
- 238000000034 method Methods 0.000 description 12
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 11
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 11
- 238000002425 crystallisation Methods 0.000 description 10
- 230000008025 crystallization Effects 0.000 description 10
- 239000012535 impurity Substances 0.000 description 8
- 239000003960 organic solvent Substances 0.000 description 6
- 239000007789 gas Substances 0.000 description 5
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 3
- 238000000921 elemental analysis Methods 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- 239000004809 Teflon Substances 0.000 description 2
- 229920006362 Teflon® Polymers 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 238000011002 quantification Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- 229910012258 LiPO Inorganic materials 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- OWKYFCJSPXWGRX-UHFFFAOYSA-H P(=O)([O-])([O-])F.[Li+].[Li+].[Li+].[Li+].[Li+].[Li+].P(=O)([O-])([O-])F.P(=O)([O-])([O-])F Chemical compound P(=O)([O-])([O-])F.[Li+].[Li+].[Li+].[Li+].[Li+].[Li+].P(=O)([O-])([O-])F.P(=O)([O-])([O-])F OWKYFCJSPXWGRX-UHFFFAOYSA-H 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000007810 chemical reaction solvent Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- SXWUDUINABFBMK-UHFFFAOYSA-L dilithium;fluoro-dioxido-oxo-$l^{5}-phosphane Chemical compound [Li+].[Li+].[O-]P([O-])(F)=O SXWUDUINABFBMK-UHFFFAOYSA-L 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000005496 eutectics Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 229910001386 lithium phosphate Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- TWQULNDIKKJZPH-UHFFFAOYSA-K trilithium;phosphate Chemical compound [Li+].[Li+].[Li+].[O-]P([O-])([O-])=O TWQULNDIKKJZPH-UHFFFAOYSA-K 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
Classifications
-
- 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
Landscapes
- Primary Cells (AREA)
- Secondary Cells (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、リチウム電池およ
びリチウムイオン電池用電解質として有用なヘキサフル
オロリン酸リチウムの製造方法に関する。TECHNICAL FIELD The present invention relates to a method for producing lithium hexafluorophosphate, which is useful as an electrolyte for lithium batteries and lithium ion batteries.
【０００２】[0002]
【従来技術】ヘキサフルオロリン酸リチウムの製造方法
としては種々提案されており、例えば無溶媒で固体のフ
ッ化リチウムと気体の五フッ化リンを反応させる方法
（特開昭６４−７２９０１号）等がある。この方法にお
いては、フッ化リチウムの表面に反応生成物の被膜が形
成され、完全には反応が進行せず未反応のフッ化リチウ
ムが残存する。2. Description of the Related Art Various methods for producing lithium hexafluorophosphate have been proposed, for example, a method of reacting solid lithium fluoride with gaseous phosphorus pentafluoride in the absence of a solvent (Japanese Patent Laid-Open No. 64-72901). There is. In this method, a film of the reaction product is formed on the surface of lithium fluoride, the reaction does not proceed completely, and unreacted lithium fluoride remains.
【０００３】また、無水フッ化水素を溶媒として、溶解
したフッ化リチウムと気体状の五フッ化リンを反応させ
る方法（Ｊ．Ｃｈｅｍ．Ｓｏｃ．Ｐａｒｔ４，４４０８
（１９６３））がある。この方法においては、蒸気圧の
高い無水フッ化水素を溶媒として使用するため、ハンド
リングが困難であり、また、反応後に結晶として取り出
したヘキサフルオロリン酸リチウム中に不純物としてフ
ッ化水素が残存する。この不純物のフッ化水素はリチウ
ム電池として使用する場合、その電池反応を阻害するも
のであり、好ましくない。A method of reacting dissolved lithium fluoride with gaseous phosphorus pentafluoride using anhydrous hydrogen fluoride as a solvent (J. Chem. Soc. Part 4, 4408).
(1963)). In this method, since anhydrous hydrogen fluoride having a high vapor pressure is used as a solvent, it is difficult to handle, and hydrogen fluoride remains as an impurity in lithium hexafluorophosphate taken out as crystals after the reaction. When used as a lithium battery, this impurity hydrogen fluoride inhibits the battery reaction and is not preferred.
【０００４】また、有機溶媒にヘキサフルオロリン酸リ
チウム溶解して再結晶することにより、不純物の除去を
行う方法もいくつか提案されているが、有機溶媒から結
晶化する際に、溶媒分子とヘキサフルオロリン酸リチウ
ム分子が付加物を形成し、得られた結晶はヘキサフルオ
ロリン酸リチウム・有機溶媒の付加物結晶となり、この
溶媒分子を減圧等で強制的に除去するとヘキサフルオロ
リン酸リチウムが、非常に表面積の大きい活性なものと
なり、分解が促進されるため、この方法も実用的ではな
い。 このように従来の方法においては、いずれも反応
収率、反応の制御のしやすさ、得られる製品の純度等の
点で必ずしも満足のできるものではなかった。Several methods have been proposed to remove impurities by dissolving lithium hexafluorophosphate in an organic solvent and recrystallizing it. However, when crystallizing from an organic solvent, the solvent molecules and hexa Lithium fluorophosphate molecules form an adduct, the resulting crystals become adduct crystals of lithium hexafluorophosphate / organic solvent, and when this solvent molecule is forcibly removed by reduced pressure, lithium hexafluorophosphate, This method is also impractical because it becomes very active with a large surface area and promotes decomposition. As described above, none of the conventional methods is always satisfactory in terms of reaction yield, controllability of the reaction, purity of the obtained product, and the like.
【０００５】[0005]
【問題点を解決するための具体的手段】本発明者らは、
かかる従来技術の問題点に鑑み鋭意検討の結果、ジメチ
ルカーボネート中で製造することにより、不純物の少な
いヘキサフルオロリン酸リチウムができることを見いだ
し、本発明に到達したものである。[Means for Solving the Problems] The present inventors
As a result of intensive studies in view of the problems of the prior art, it was found that lithium hexafluorophosphate containing a small amount of impurities can be produced by manufacturing in dimethyl carbonate, and the present invention has been achieved.
【０００６】すなわち本発明は、ジメチルカーボネート
中でフッ化リチウムと五フッ化リンとを反応させること
により得られるヘキサフルオロリン酸リチウムをジメチ
ルカーボネート溶液中より、−２０℃から１５０℃の温
度範囲でジメチルカーボネートを蒸発させ、溶液を濃縮
する方法により、５０μｍ以上の粒径のヘキサフルオロ
リン酸リチウム結晶を晶出させるものであり、またヘキ
サフルオロリン酸リチウムをジメチルカーボネート中に
溶解し、−２０℃から１５０℃の温度範囲で蒸発濃縮に
より再結晶し、粒径が５０μｍ以上の結晶を得るもの
で、さらに得られた結晶を−２０℃から１５０℃の温度
範囲で乾燥することを特徴とするヘキサフルオロリン酸
リチウムの製造方法を提供するものである。That is, according to the present invention, lithium hexafluorophosphate obtained by reacting lithium fluoride and phosphorus pentafluoride in dimethyl carbonate is dissolved in a dimethyl carbonate solution at a temperature range of -20 ° C to 150 ° C. By evaporating dimethyl carbonate and concentrating the solution, lithium hexafluorophosphate crystals having a particle size of 50 μm or more are crystallized, and lithium hexafluorophosphate is dissolved in dimethyl carbonate to obtain -20 ° C. To obtain a crystal having a particle size of 50 μm or more by recrystallization by evaporative concentration in the temperature range of ˜150 ° C., and further drying the obtained crystal in the temperature range of −20 ° C. to 150 ° C. A method for producing lithium fluorophosphate is provided.
【０００７】本発明の製造方法は、反応収率が高く、反
応の制御も容易で、製品の純度、結晶の性状の点でも十
分満足できるものである。本発明において、問題となっ
ているヘキサフルオロリン酸リチウム中の不純物である
フッ化水素は、従来の方法では、反応溶媒として使用す
る無水フッ化水素から来ることは明らかである。そこ
で、溶媒として他の有機溶媒を使用することが有効であ
る。有機溶媒から一般的な方法で、結晶を晶出する場合
は、ヘキサフルオロリン酸リチウムと溶媒の相互作用が
強いため、ヘキサフルオロリン酸リチウム１分子に対し
て、溶媒が１から６分子程度配位した状態で付加物結晶
を形成するので、純粋なヘキサフルオロリン酸リチウム
を得るためには、真空乾燥を行い付加した溶媒分子を除
去する必要がある。しかし、一旦付加物結晶になったも
のから、溶媒分子のみを除去するためには、多大な労力
と時間を要するため好ましい方法とは思われない。しか
も、溶媒分子を除去した後の結晶は、表面がポーラス
で、粒径も１０μｍ以下の微細な凝集晶となり、表面の
活性があがることにより、保存中に熱による自己分解
（例えば、ＬｉＰＦ6→ＬｉＦ＋ＰＦ5）や雰囲気中のわ
ずかな水分による加水分解（例えば、ＬｉＰＦ6＋２Ｈ2
Ｏ→ＬｉＰＯ2Ｆ2 ＋ ４ＨＦ）が起こるという新たな
問題が発生する。このようなことにより、有機溶媒から
のヘキサフルオロリン酸リチウムの晶出は非常に困難で
あると考えられていた。The production method of the present invention has a high reaction yield, is easy to control the reaction, and is sufficiently satisfactory in terms of product purity and crystal properties. In the present invention, it is clear that hydrogen fluoride, which is an impurity in lithium hexafluorophosphate in question, comes from anhydrous hydrogen fluoride used as a reaction solvent in the conventional method. Therefore, it is effective to use another organic solvent as the solvent. When a crystal is crystallized from an organic solvent by a general method, since the interaction between lithium hexafluorophosphate and the solvent is strong, about 1 to 6 molecules of the solvent are distributed to one molecule of lithium hexafluorophosphate. Since an adduct crystal is formed in the aligned state, it is necessary to perform vacuum drying to remove added solvent molecules in order to obtain pure lithium hexafluorophosphate. However, it takes a great deal of labor and time to remove only the solvent molecules from the adduct crystals, which is not a preferable method. Moreover, the crystal after removing the solvent molecules has a porous surface and becomes a fine agglomerated crystal with a particle size of 10 μm or less, and the surface activity is increased, so that the crystal self-decomposes by heat during storage (for example, LiPF 6 → LiF + PF 5 ) or hydrolysis by a slight amount of water in the atmosphere (for example, LiPF 6 + 2H 2
A new problem occurs that O → LiPO 2 F 2 + 4HF) occurs. Due to these reasons, it was thought that crystallization of lithium hexafluorophosphate from an organic solvent was extremely difficult.
【０００８】そこで、本発明者らが種々検討した結果、
有機非水溶媒からヘキサフルオロリン酸リチウムの結晶
を晶出する場合、２０℃以上の温度領域で蒸発濃縮にて
晶出することにより、結晶の相転移が起こり、付加物で
はない純粋なヘキサフルオロリン酸リチウムの結晶が得
られることを見出し、既に特許出願をしている。Then, as a result of various studies by the present inventors,
When a crystal of lithium hexafluorophosphate is crystallized from an organic non-aqueous solvent, a crystal phase transition occurs by crystallizing by evaporation and concentration in a temperature range of 20 ° C. or higher, and pure hexafluorophosphate that is not an adduct. We have found that crystals of lithium phosphate can be obtained and have already filed a patent application.
【０００９】しかし、さらに検討を進めていく中で、ジ
メチルカーボネートのみが特異的に２０℃より低い温度
領域においても、付加物結晶を形成しないことを見いだ
したものである。However, during further study, it was discovered that only dimethyl carbonate does not specifically form an adduct crystal even in a temperature range lower than 20.degree.
【００１０】本発明の製造方法は、このジメチルカーボ
ネートの特異性を利用したものであり、このジメチルカ
ーボネートを溶媒として使用すれば、他の溶媒のように
シビアな温度コントロールする必要もなく、効率的にヘ
キサフルオロリン酸リチウムを製造することが可能とな
る。The production method of the present invention utilizes the specificity of this dimethyl carbonate. If this dimethyl carbonate is used as a solvent, it is not necessary to perform severe temperature control like other solvents, and it is efficient. It becomes possible to produce lithium hexafluorophosphate.
【００１１】本発明の製造方法では、ジメチルカーボネ
ート中で、ヘキサフルオロリン酸リチウムの合成を行
う。上記溶媒中に原料であるフッ化リチウムの溶解度は
非常に小さいため、溶媒に分散した状態で五フッ化リン
のガスを吹き込み反応を行う。ここで、生成したヘキサ
フルオロリン酸リチウムは非常に溶解度が大きいので、
溶媒中に溶解して、表面に被膜として残ることがないた
めに反応は完全に進行する。In the production method of the present invention, lithium hexafluorophosphate is synthesized in dimethyl carbonate. Since the raw material lithium fluoride has a very low solubility in the solvent, phosphorus pentafluoride gas is blown into the solvent to carry out the reaction. Here, since the generated lithium hexafluorophosphate has a very high solubility,
The reaction proceeds completely because it dissolves in the solvent and does not remain as a film on the surface.
【００１２】この反応を行う際の温度は、下限が−４０
℃、好ましくは０℃で、上限は１００℃、好ましくは６
０℃である。反応温度が−４０℃未満では、溶媒が凝固
するため反応が進行しない。また、１００℃より大きい
場合、溶媒と五フッ化リンの反応が起こり、着色や粘度
増加の原因となるため好ましくない。The lower limit of the temperature for carrying out this reaction is -40.
℃, preferably 0 ℃, the upper limit is 100 ℃, preferably 6
It is 0 ° C. If the reaction temperature is lower than -40 ° C, the solvent solidifies and the reaction does not proceed. On the other hand, if the temperature is higher than 100 ° C., the reaction between the solvent and phosphorus pentafluoride occurs, which causes coloring and viscosity increase, which is not preferable.
【００１３】フッ化リチウムの量は、溶媒１リットルに
対して、２００ｇ以下、好ましくは１００ｇ以下であ
る。フッ化リチウムの量が溶媒に対して、２００ｇより
多い場合は生成物が飽和になり、フッ化リチウム表面に
被膜が生成し、未反応のフッ化リチウムが残存するうえ
に溶液の粘度が上昇するため、濾過等の分離操作が困難
になる。 五フッ化リンの量は、フッ化リチウムに対し
て当量以上あれば良いが、過剰に系内に導入した場合、
溶液中に吸収されるため、反応後に加熱、減圧等の操作
により除去する必要がある。The amount of lithium fluoride is 200 g or less, preferably 100 g or less, per liter of solvent. When the amount of lithium fluoride is more than 200 g with respect to the solvent, the product becomes saturated, a film is formed on the surface of lithium fluoride, unreacted lithium fluoride remains, and the viscosity of the solution increases. Therefore, separation operation such as filtration becomes difficult. The amount of phosphorus pentafluoride may be equivalent to or more than lithium fluoride, but if excessively introduced into the system,
Since it is absorbed in the solution, it is necessary to remove it by heating, depressurizing or the like after the reaction.
【００１４】この反応において、原料の五フッ化リン、
および生成物のヘキサフルオロリン酸リチウムは、水分
により容易に加水分解を受けるので、水分を含まない雰
囲気で反応を実施する必要がある。すなわち、真空中や
窒素等の不活性ガス雰囲気中で反応を行うことが好まし
い。In this reaction, the raw material phosphorus pentafluoride,
Since the product lithium hexafluorophosphate is easily hydrolyzed by water, it is necessary to carry out the reaction in an atmosphere containing no water. That is, it is preferable to carry out the reaction in vacuum or in an atmosphere of an inert gas such as nitrogen.
【００１５】得られたヘキサフルオロリン酸リチウムの
溶液を適当な方法で精製した後、晶析操作を行い、結晶
を取り出す。また、本発明において、従来の方法で製造
したヘキサフルオロリン酸リチウム結晶をジメチルカー
ボネート中に溶解した後、晶析操作を行い再結晶化す
る。ここで、再結晶だけでも十分ではあるが、溶液の段
階で適当な方法により、フッ化水素その他の不純物の精
製をさらに行えばより効果的である。The obtained solution of lithium hexafluorophosphate is purified by an appropriate method and then subjected to a crystallization operation to take out crystals. Further, in the present invention, the lithium hexafluorophosphate crystal produced by the conventional method is dissolved in dimethyl carbonate and then recrystallized by performing a crystallization operation. Here, recrystallization alone is sufficient, but it is more effective if hydrogen fluoride and other impurities are further purified by an appropriate method at the solution stage.
【００１６】本発明の製造方法において、ポイントとな
るのはジメチルカーボネートを溶媒として使用して、ヘ
キサフルオロリン酸リチウム結晶を晶出させることであ
る。ジメチルカーボネートとヘキサフルオロリン酸リチ
ウムの系では、他の溶媒と異なり共晶点が−２０℃であ
るため、晶析の温度範囲は下限が−２０℃、好ましくは
−１０℃で、上限は１５０℃、好ましくは９０℃であ
る。この温度が−２０℃未満ではヘキサフルオロリン酸
リチウムとジメチルカーボネートの付加物結晶となるた
め好ましくない。また、１５０℃より高い温度ではヘキ
サフルオロリン酸リチウムの分解、溶媒との反応が起こ
るため好ましくない。In the production method of the present invention, the point is to use dimethyl carbonate as a solvent to crystallize lithium hexafluorophosphate crystals. In the system of dimethyl carbonate and lithium hexafluorophosphate, the eutectic point is −20 ° C. unlike other solvents, so the lower limit of the crystallization temperature range is −20 ° C., preferably −10 ° C., and the upper limit is 150 ° C. ℃, preferably 90 ℃. If this temperature is less than -20 ° C, it will be an adduct crystal of lithium hexafluorophosphate and dimethyl carbonate, which is not preferable. Further, at a temperature higher than 150 ° C., decomposition of lithium hexafluorophosphate and reaction with a solvent occur, which is not preferable.
【００１７】晶析の手段は、この温度領域では溶解度の
温度依存性が小さくなるため蒸発濃縮により、結晶を晶
出する方法が好ましい。結晶の晶出後、ろ過により固液
分離するが、結晶表面に付着した溶液が室温に戻るとジ
メチルカーボネート以外の溶媒を用いた場合は、付加物
結晶が生成し、得られた結晶が純粋な結晶と付加物結晶
の混合物となるため、熱ろ過、および２０℃以上での乾
燥が必要となるが、ジメチルカーボネートの場合は、−
２０℃から１５０℃の温度範囲での操作が可能であるた
め、設備面でも非常にシンプルになる。As a means of crystallization, a method of crystallizing a crystal by evaporative concentration is preferable because the temperature dependence of the solubility becomes small in this temperature range. After crystallization of crystals, solid-liquid separation is performed by filtration, but when the solution adhering to the crystal surface returns to room temperature and a solvent other than dimethyl carbonate is used, adduct crystals are produced and the obtained crystals are pure. Since it becomes a mixture of crystals and adduct crystals, hot filtration and drying at 20 ° C. or higher are required, but in the case of dimethyl carbonate,
Since it can be operated in the temperature range of 20 ° C to 150 ° C, it is very simple in terms of equipment.
【００１８】以上の方法によりヘキサフルオロリン酸リ
チウムを晶出すれば、５０μｍ以上の粒径を持つ結晶が
容易に得られる。さらに晶析条件をコントロールすれ
ば、１ｍｍ以上の結晶も得られる。このようにして得ら
れたヘキサフルオロリン酸リチウムの結晶は、単結晶ま
たは一次凝集晶であり、非常に純度が高く、保存時の安
定性においても優れている。By crystallizing lithium hexafluorophosphate by the above method, crystals having a particle size of 50 μm or more can be easily obtained. Further, if the crystallization conditions are controlled, crystals of 1 mm or more can be obtained. The crystals of lithium hexafluorophosphate thus obtained are single crystals or primary agglomerated crystals, have extremely high purity, and are excellent in stability during storage.
【００１９】[0019]
【実施例】以下実施例により本発明を具体的に説明する
が、本発明はかかる実施例により限定されるものではな
い。EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples.
【００２０】実施例１
テフロン製反応器中で９０ｇジメチルカーボネートに
５．２ｇフッ化リチウムを添加して、混合分散した。こ
の分散液を冷却して２０℃を維持しながら、ガス導入管
を通して、五フッ化リンガスをバブリングした。ジメチ
ルカーボネート中に分散されたフッ化リチウムが消失し
た時点で反応を終了した。このときの五フッ化リンの消
費量は２６ｇであった。Example 1 In a Teflon reactor, 5.2 g of lithium fluoride was added to 90 g of dimethyl carbonate and mixed and dispersed. While the dispersion was cooled and maintained at 20 ° C., phosphorus pentafluoride gas was bubbled through the gas introduction pipe. The reaction was terminated when the lithium fluoride dispersed in dimethyl carbonate disappeared. At this time, the amount of phosphorus pentafluoride consumed was 26 g.
【００２１】得られた溶液を特に温度制御せずに、撹拌
しながら１ｔｏｒｒ減圧で蒸発晶析を行った。気化熱を
奪われることにより、溶液の温度は５℃になった。ジメ
チルカーボネートが６５ｇ蒸発した時点で、晶出した結
晶を濾別し、室温で真空乾燥した。以上のようにしてヘ
キサフルオロリン酸リチウム１５ｇを得た。得られたヘ
キサフルオロリン酸リチウムの平均粒径は３００μｍ
で、元素分析により組成を確認したところ、付加物を含
まない純粋なヘキサフルオロリン酸リチウムであった。
また、不純物のフッ化水素濃度は５０ｐｐｍ以下（定量
下限）であった。The resulting solution was subjected to evaporative crystallization under reduced pressure of 1 torr while stirring without particular temperature control. By removing the heat of vaporization, the temperature of the solution became 5 ° C. When 65 g of dimethyl carbonate had evaporated, the crystallized crystals were filtered off and dried under vacuum at room temperature. As described above, 15 g of lithium hexafluorophosphate was obtained. The average particle size of the obtained lithium hexafluorophosphate is 300 μm.
Then, when the composition was confirmed by elemental analysis, it was pure lithium hexafluorophosphate containing no adduct.
Moreover, the hydrogen fluoride concentration of impurities was 50 ppm or less (the lower limit of quantification).
【００２２】実施例２
フッ化水素を３０００ｐｐｍ含有するヘキサフルオロリ
ン酸リチウム４５ｇをジメチルカーボネート７５ｇに溶
解した。この溶液に種晶として、フッ化水素を１００ｐ
ｐｍ含有するヘキサフルオロリン酸リチウムを４ｇ添加
したのち、液温を−５℃に保持して撹拌しながら１ｔｏ
ｒｒ減圧で蒸発晶析を行った。ジメチルカーボネートが
４０ｇ蒸発した時点で、晶出した結晶を濾別し、室温で
真空乾燥した。以上のようにしてヘキサフルオロリン酸
リチウム２９ｇを得た。得られたヘキサフルオロリン酸
リチウムの平均粒径は３２０μｍで、元素分析により組
成を確認したところ、付加物を含まない純粋なヘキサフ
ルオロリン酸リチウムであった。また、不純物のフッ化
水素濃度は５０ｐｐｍ以下（定量下限）であった。Example 2 45 g of lithium hexafluorophosphate containing 3000 ppm of hydrogen fluoride was dissolved in 75 g of dimethyl carbonate. In this solution, 100 p of hydrogen fluoride was used as a seed crystal.
After adding 4 g of lithium hexafluorophosphate containing pm, the liquid temperature was kept at -5 ° C and stirred at 1 to
Evaporative crystallization was performed under reduced pressure of rr. When 40 g of dimethyl carbonate had evaporated, the crystallized crystals were filtered off and dried under vacuum at room temperature. As described above, 29 g of lithium hexafluorophosphate was obtained. The average particle size of the obtained lithium hexafluorophosphate was 320 μm, and when the composition was confirmed by elemental analysis, it was pure lithium hexafluorophosphate containing no adduct. Moreover, the hydrogen fluoride concentration of impurities was 50 ppm or less (the lower limit of quantification).
【００２３】比較例１
テフロン製反応器中で９０ｇジエチルカーボネートに
５．２ｇフッ化リチウムを添加して、混合分散した。こ
の分散液を冷却して２０℃を維持しながら、ガス導入管
を通して、五フッ化リンガスをバブリングした。ジエチ
ルカーボネート中に分散されたフッ化リチウムが消失し
た時点で反応を終了した。このときの五フッ化リンの消
費量は２６ｇであった。Comparative Example 1 In a Teflon reactor, 5.2 g of lithium fluoride was added to 90 g of diethyl carbonate and mixed and dispersed. While the dispersion was cooled and maintained at 20 ° C., phosphorus pentafluoride gas was bubbled through the gas introduction pipe. The reaction was terminated when the lithium fluoride dispersed in diethyl carbonate disappeared. At this time, the amount of phosphorus pentafluoride consumed was 26 g.
【００２４】得られた溶液を特に温度制御せずに、撹拌
しながら１ｔｏｒｒ減圧で蒸発晶析を行った。気化熱を
奪われることにより、溶液の温度は１０℃になった。ジ
エチルカーボネートが３８ｇ蒸発した時点で、全体が凝
固したため、この結晶を室温で真空乾燥した。The solution thus obtained was subjected to evaporative crystallization under reduced pressure of 1 torr while stirring without controlling the temperature. By removing the heat of vaporization, the temperature of the solution became 10 ° C. When 38 g of diethyl carbonate had evaporated, the whole solidified, and thus the crystals were vacuum dried at room temperature.
【００２５】以上のようにして得られた結晶の平均粒径
は６００μｍで、元素分析により組成を確認したとこ
ろ、ヘキサフルオロリン酸リチウム１分子に対して、ジ
エチルカーボネートが２分子配位した付加物結晶であっ
た。The crystals thus obtained had an average particle size of 600 μm, and their composition was confirmed by elemental analysis. As a result, one molecule of lithium hexafluorophosphate was adducted with two molecules of diethyl carbonate. It was a crystal.
【００２６】[0026]
【発明の効果】本発明によれば、従来の製造方法に比
べ、非常に純度が高く、保存時の安定性においても優れ
たヘキサフルオロリン酸リチウムを提供することができ
る。Industrial Applicability According to the present invention, lithium hexafluorophosphate can be provided which has an extremely high purity and is excellent in stability during storage as compared with the conventional production method.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 川島 忠幸 山口県宇部市大字沖宇部5253番地 セン トラル硝子株式会社化学研究所内 (72)発明者 佐々木 広美 山口県宇部市大字沖宇部5253番地 セン トラル硝子株式会社化学研究所内 (56)参考文献 特開 平６−298506（ＪＰ，Ａ) 特開 昭59−81870（ＪＰ，Ａ) 特開 昭58−161910（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C01B 25/455 ＣＡ（ＳＴＮ)─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadayuki Kawashima 5253 Oki Obe, Ube City, Yamaguchi Prefecture Central Glass Co., Ltd. Chemical Research Laboratory (72) Inventor Hiromi Sasaki 5253 Oki Ube, Ube City Yamaguchi Prefecture Central Glass (56) References JP-A-6-298506 (JP, A) JP-A-59-81870 (JP, A) JP-A-58-161910 (JP, A) (58) Fields investigated ( Int.Cl. 7 , DB name) C01B 25/455 CA (STN)
Claims (6)
サフルオロリン酸リチウムとジメチルカーボネートから
なる溶液中より、−２０℃から１５０℃の温度範囲でジ
メチルカーボネートを蒸発、濃縮により晶出させること
を特徴とするヘキサフルオロリン酸リチウムの製造方
法。1. Lithium hexafluorophosphate is crystallized by evaporating and condensing dimethyl carbonate from a solution of lithium hexafluorophosphate and dimethyl carbonate in a temperature range of −20 ° C. to 150 ° C. A method for producing lithium hexafluorophosphate.
ムの粒径が、５０μｍ以上の結晶であることを特徴とす
る請求項１記載のヘキサフルオロリン酸リチウムの製造
方法。2. The method for producing lithium hexafluorophosphate according to claim 1, wherein the crystallized lithium hexafluorophosphate is a crystal having a particle size of 50 μm or more.
ルオロリン酸リチウムが、ジメチルカーボネート中でフ
ッ化リチウムと五フッ化リンとを反応させたものである
ことを特徴とする請求項１記載のヘキサフルオロリン酸
リチウムの製造方法。3. The hexafluoroline according to claim 1, wherein the lithium hexafluorophosphate in the dimethyl carbonate solution is a reaction of lithium fluoride and phosphorus pentafluoride in dimethyl carbonate. Method for producing lithium oxide.
ルカーボネート中に溶解し、−２０℃から１５０℃の温
度範囲で蒸発濃縮により再結晶させことを特徴とするヘ
キサフルオロリン酸リチウムの製造方法。4. A method for producing lithium hexafluorophosphate, which comprises dissolving lithium hexafluorophosphate in dimethyl carbonate and recrystallizing it by evaporative concentration in the temperature range of −20 ° C. to 150 ° C.
以上の結晶であることを特徴とする請求項４記載のヘキ
サフルオロリン酸リチウムの製造方法。5. The crystal obtained by recrystallization has a particle size of 50 μm.
The method for producing lithium hexafluorophosphate according to claim 4, which is the above crystal.
法で得られたヘキサフルオロリン酸リチウム結晶を、−
２０℃から１５０℃の温度範囲で乾燥することを特徴と
するヘキサフルオロリン酸リチウムの製造方法。6. The lithium hexafluorophosphate crystal obtained by the production method according to claim 1,
A method for producing lithium hexafluorophosphate, which comprises drying in a temperature range of 20 ° C to 150 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP07982797A JP3483099B2 (en) | 1997-03-18 | 1997-03-31 | Method for producing lithium hexafluorophosphate |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9-64959 | 1997-03-18 | ||
| JP6495997 | 1997-03-18 | ||
| JP07982797A JP3483099B2 (en) | 1997-03-18 | 1997-03-31 | Method for producing lithium hexafluorophosphate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10316410A JPH10316410A (en) | 1998-12-02 |
| JP3483099B2 true JP3483099B2 (en) | 2004-01-06 |
Family
ID=26406107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP07982797A Expired - Fee Related JP3483099B2 (en) | 1997-03-18 | 1997-03-31 | Method for producing lithium hexafluorophosphate |
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| Country | Link |
|---|---|
| JP (1) | JP3483099B2 (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4604505B2 (en) * | 2004-02-09 | 2011-01-05 | 三菱化学株式会社 | Method for producing lithium difluorophosphate, non-aqueous electrolyte and non-aqueous electrolyte secondary battery using the same |
| JP5307409B2 (en) * | 2007-08-16 | 2013-10-02 | ステラケミファ株式会社 | Method for producing phosphorus pentafluoride and hexafluorophosphate |
| JP5165364B2 (en) * | 2007-12-25 | 2013-03-21 | ステラケミファ株式会社 | Method for producing hexafluorophosphate |
| JP5351463B2 (en) * | 2008-08-08 | 2013-11-27 | ステラケミファ株式会社 | Method for producing hexafluorophosphate |
| JP2010042937A (en) | 2008-08-08 | 2010-02-25 | Stella Chemifa Corp | Method for producing phosphorus pentafluoride and hexafluorophosphates |
| JP4616925B2 (en) * | 2008-12-02 | 2011-01-19 | ステラケミファ株式会社 | Method for producing difluorophosphate |
| JP4560132B2 (en) * | 2008-12-02 | 2010-10-13 | ステラケミファ株式会社 | Method for producing difluorophosphate |
| CN102036912B (en) | 2008-12-02 | 2013-02-27 | 斯泰拉化工公司 | Method for producing difluorophosphate, nonaqueous electrolytic solution, and nonaqueous electrolyte secondary battery |
| JP5824013B2 (en) * | 2013-08-21 | 2015-11-25 | ステラケミファ株式会社 | Method for producing phosphorus pentafluoride and hexafluorophosphate |
| NL2020683B1 (en) * | 2018-03-29 | 2019-03-19 | The South African Nuclear Energy Corporation Soc Ltd | Production of lithium hexafluorophosphate |
| CN114737206B (en) * | 2022-04-29 | 2022-11-11 | 福建省龙德新能源有限公司 | Preparation method of lithium hexafluorophosphate |
| CN114890402B (en) * | 2022-05-26 | 2024-05-03 | 刘文洁 | Preparation method of hexafluorophosphate |
| CN116081593A (en) * | 2023-01-17 | 2023-05-09 | 山东氟能化工材料有限公司 | Preparation method of liquid lithium hexafluorophosphate |
-
1997
- 1997-03-31 JP JP07982797A patent/JP3483099B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10316410A (en) | 1998-12-02 |
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