JP2018056411A5

JP2018056411A5 -

Info

Publication number: JP2018056411A5
Application number: JP2016192475A
Authority: JP
Filing date: 2016-09-30
Publication date: 2019-09-05
Anticipated expiration: 2036-09-30

Claims

正極と負極がセパレータを介して積層された積層体、並びにリチウムイオンを含む非水系電解液を含む非水系リチウム型蓄電素子であって、
前記正極は、リチウム化合物を含み、
前記正極は、正極集電体と、該正極集電体の片面又は両面に正極活物質層とを有し、前該正極活物質層は、活性炭からなる正極活物質を含有し、
前記負極は、負極集電体と、該負極集電体の片面又は両面に負極活物質層とを有し、該負極活物質層は、リチウムイオンを吸蔵・放出できる負極活物質を含有し、
前記積層体の厚み方向最外層における負極の負極活物質層を上面視した際の中心のリチウムイオン濃度をＣ_１ｏ、前記積層体の厚み方向最内層における負極の負極活物質層を上面視した際の中心のリチウムイオン濃度をＣ_１ｉとするときＣ_１ｏ/Ｃ_１ｉが０．８５以上１．１５以下であり、
前記負極活物質層の周縁部２０％の面積領域よりも前記負極活物質層の中心部８０％の面積領域において、リチウムイオンの濃度が高く、
前記リチウム化合物の平均粒子径をＸ_１とするとき、０．１μｍ≦Ｘ_１≦１０μｍであり、前記正極活物質の平均粒子径をＹ_１とするとき、２μｍ≦Ｙ_１≦２０μｍであり、Ｘ_１＜Ｙ_１であり、かつ、前記正極中に含まれるリチウム化合物の量が１質量％以上５０質量％以下である、前記非水系リチウム型蓄電素子。 A laminate in which a positive electrode and a negative electrode are laminated via a separator, and a non-aqueous lithium storage element including a non-aqueous electrolyte containing lithium ions,
The positive electrode includes a lithium compound,
The positive electrode has a positive electrode current collector and a positive electrode active material layer on one or both sides of the positive electrode current collector, and the positive electrode active material layer contains a positive electrode active material made of activated carbon,
The negative electrode has a negative electrode current collector and a negative electrode active material layer on one or both sides of the negative electrode current collector, the negative electrode active material layer contains a negative electrode active material capable of inserting and extracting lithium ions,
When the negative electrode active material layer of the negative electrode in the thickness direction outermost layer of the laminate is viewed from above, the central lithium ion concentration is C _1o , and when the negative electrode active material layer of the negative electrode in the thickness direction innermost layer of the laminate is viewed from above _{C 1o} / _{C 1i} when the lithium ion concentration of the centers of the _{C 1i} is 0.85 to 1.15,
The concentration of lithium ions is higher in the area of 80% of the central part of the negative electrode active material layer than in the area of 20% of the peripheral part of the negative electrode active material layer,
When the average particle diameter of the lithium compound and _{X 1,} a 0.1μm ≦ _{X 1} ≦ 10μm, when the average particle diameter of the positive electrode active material and _{Y 1,} a 2μm ≦ _{Y 1} ≦ 20μm, X ₁ <Y ₁ and the amount of the lithium compound contained in the positive electrode is 1% by mass or more and 50% by mass or less.

前記積層体の厚み方向最外層における負極の負極活物質層を上面視した際の中心の負極活物質層の厚みをＴ_１ｏ、前記積層体の厚み方向最内層における負極の負極活物質層を上面視した際の中心の負極活物質層の厚みをＴ_１ｉとするとき、Ｔ_１ｏ/Ｔ_１ｉが０．８５以上１．１５以下である、請求項１に記載の非水系リチウム蓄電素子。 T _{1o is} the thickness of the negative electrode active material layer at the center when the negative electrode active material layer of the negative electrode in the outermost layer in the thickness direction of the laminate is viewed from above, and the negative electrode active material layer of the negative electrode in the innermost layer in the thickness direction of the laminate is the upper surface when the thickness of the negative electrode active material layer in the center when the viewing and _{_{_{T 1i,}} T} _1o / _{T 1i} is 0.85 to 1.15, the non-aqueous lithium electric storage device according to claim 1.

正極と負極がセパレータを介して捲回された捲回体、並びにリチウムイオンを含む非水系電解液からなる非水系リチウム型蓄電素子であって、
前記正極は、リチウム化合物を含み、
前記正極は、正極集電体と、該正極集電体の片面又は両面に正極活物質層とを有し、該正極活物質層は、活性炭からなる正極活物質を含有し、
前記負極は、負極集電体と、該負極集電体の片面又は両面に負極活物質層とを有し、該負極活物質層は、リチウムイオンを吸蔵・放出できる負極活物質を含有し、
前記捲回体の正極と対向し、かつ、周縁部を除く半径方向最外周の負極の負極活物質層を上面視した際の中心のリチウムイオン濃度をＣ_２ｏ、前記捲回体の正極と対向しかつ周縁部を除く半径方向最内層における負極の負極活物質層を上面視した際の中心のリチウムイオン濃度をＣ_２ｉとするとき、Ｃ_２ｏ/Ｃ_２ｉが０．８５以上１．１５以下であり、
前記負極活物質層の周縁部２０％の面積領域よりも前記負極活物質層の中心部８０％の面積領域において、リチウムイオンの濃度が高く、
前記リチウム化合物の平均粒子径をＸ_１とするとき、０．１μｍ≦Ｘ_１≦１０μｍであり、正極活物質の平均粒子径をＹ_１とするとき、２μｍ≦Ｙ_１≦２０μｍであり、Ｘ_１＜Ｙ_１であり、かつ、前記正極中に含まれるリチウム化合物の量が１質量％以上５０質量％以下である、前記非水系リチウム型蓄電素子。 A non-aqueous lithium storage element comprising a wound body in which a positive electrode and a negative electrode are wound through a separator, and a non-aqueous electrolyte containing lithium ions,
The positive electrode includes a lithium compound,
The positive electrode has a positive electrode current collector and a positive electrode active material layer on one or both sides of the positive electrode current collector, the positive electrode active material layer contains a positive electrode active material made of activated carbon,
The negative electrode has a negative electrode current collector and a negative electrode active material layer on one or both sides of the negative electrode current collector, the negative electrode active material layer contains a negative electrode active material capable of inserting and extracting lithium ions,
Opposite to the positive electrode of the wound body, and the center lithium ion concentration of the negative electrode active material layer of the negative electrode in the outermost radial direction excluding the peripheral portion is C _2o , facing the positive electrode of the wound _body when the lithium ion concentration in the center when the anode active material layer of the negative electrode was viewed in the radial direction innermost layer except for the life-and-death periphery and C _{_2i,} C _2o / C _2i is 0.85 to 1.15 Yes,
The concentration of lithium ions is higher in the area of 80% of the central part of the negative electrode active material layer than in the area of 20% of the peripheral part of the negative electrode active material layer,
When the average particle diameter of the lithium compound is X ₁ , 0.1 μm ≦ X ₁ ≦ 10 μm, and when the average particle diameter of the positive electrode active material is Y ₁ , 2 μm ≦ Y ₁ ≦ 20 μm and X ₁ The non-aqueous lithium storage element, wherein <Y ₁ and the amount of the lithium compound contained in the positive electrode is 1% by mass or more and 50% by mass or less.

前記捲回体の正極と対向し、かつ、周縁部を除く半径方向最外周の負極の負極活物質層を上面視した際の中心の厚みをＴ_２ｏ、前記捲回体の正極と対向しかつ周縁部を除く半径方向最内層における負極の負極活物質層を上面視した際の中心の厚みをＴ_２ｉとするとき、Ｔ_２ｏ/Ｔ_２ｉが０．８５以上１．１５以下である、請求項３に記載の非水系リチウム蓄電素子。 The center thickness of the negative electrode active material layer of the negative electrode at the outermost radial direction excluding the peripheral portion is T _2o , facing the positive electrode of the wound _body , and facing the positive electrode of the wound _body ; when the thickness of the center when the anode active material layer of the negative electrode was viewed in the radial direction innermost layer except the peripheral part and T _{_2i,} T _2o / T _2i is 0.85 to 1.15, claims 4. A non-aqueous lithium storage element according to 3.

前記リチウム化合物は、炭酸リチウム、酸化リチウム、及び水酸化リチウムからなる群から選択される少なくとも一種のリチウム化合物である、請求項１〜４のいずれか１項に記載の非水系リチウム型蓄電素子。 The non-aqueous lithium storage element according to any one of claims 1 to 4, wherein the lithium compound is at least one lithium compound selected from the group consisting of lithium carbonate, lithium oxide, and lithium hydroxide.

前記セパレータは、多孔構造を持つポリオレフィンからなる樹脂膜を基材とし、少なくとも一方の面に無機微粒子からなる無機層が積層されてなり、
前記非水系リチウム型蓄電素子において、初期の常温放電内部抵抗をＲａ（Ω）、静電容量をＦ（Ｆ）、環境温度２５℃にて、セル電圧を２．２Ｖから３．８Ｖまで、３００Ｃのレートでの充放電サイクルを６０，０００回行った後の常温放電内部抵抗をＲｅ（Ω）、サイクル試験後の蓄電素子を４．５Ｖの定電圧充電を１時間行った後の静電容量をＦｅ（Ｆ）とするとき、以下の：
（ａ）Ｒｅ／Ｒａが０．９以上２．０以下である；及び
（ｂ）Ｆｅ／Ｆが１．０１以上である；
を満たすことを特徴とする、請求項１〜５のいずれか１項に記載の非水系リチウム型蓄電素子。 The separator is based on a resin film made of polyolefin having a porous structure, and an inorganic layer made of inorganic fine particles is laminated on at least one surface,
In the non-aqueous lithium storage element, the initial room temperature discharge internal resistance is Ra (Ω), the capacitance is F (F), the ambient temperature is 25 ° C., the cell voltage is from 2.2 V to 3.8 V, 300 C The room temperature discharge internal resistance after 60,000 charge / discharge cycles at a rate of 5 (Re) was obtained, and the capacitance after the cycle test was performed at a constant voltage of 4.5 V for 1 hour. Is Fe (F), the following:
(A) Re / Ra is 0.9 or more and 2.0 or less; and (b) Fe / F is 1.01 or more;
And satisfies the non-aqueous lithium-type storage element according to any one of claims 1-5.