今後の課題

合金系負極材料は、Liの挿入時に大きく膨張し、充放電の繰り返しで絶縁性のSEI層の 厚みが増し、電極の電子伝導度ならびにイオン伝導度が低下して、充放電性能が低下する。

SnやSi系粒子の大きな膨張を完全に抑制することは困難であるので、（1）Li挿入量を制 御して膨張量を低減する、（2）膨張時の空間を確保した電極設計で体積膨張ならびに膨張 時のストレスを緩和する、（3）電子伝導を補助する良質の導電補助材を組み込み電極抵抗 を下げる、（4）膨張収縮時の耐久性が高いバインダーを使用し活物質の脱落を防ぎ電極抵 抗の低下を最小に抑える、（5）層厚の増加しない安定な SEI 層を形成する電解液添加剤を 選択し電極抵抗の増加を抑える、（6）最適な正極と組み合わせて電池全体の性能を最適化 するなど、合金系負極材料の単独の改良のみならず、電池として総合的な視点から合金系 負極を活かすことを考えることが、実用化につながる最短方法であると考えられる。

103 研究業績

報文

1. Soichiro Kawakami and Kiyoshi Kanamura

‘Studies of tin alloy electrode materials prepared by mechanical alloying’

Electrochemistry, 82, 467 (2014).

2. Soichiro Kawakami and Kiyoshi Kanamura

‘Studies of silicon-transition metal alloy electrode materials prepared by mechanical milling’

in preparation.

3. Soichiro Kawakami and Kiyoshi Kanamura

‘Characterization of silicon nanoparticle anode and optimization of the electrode’

in preparation.

本研究に係る特許

1. 川上総一郎，小林直哉，三品伸也，浅尾昌也

“二次電池”

Japan Patent, 3359164 （2002）

2. 川上総一郎，浅尾昌也，小林直哉，小鈴武，木村浩直

“電極構造体、二次電池及びそれらの製造方法”

Japan Patent, 3359164（2004）

3. 川上総一郎，浅尾昌也

“二次電池用負極電極材、電極構造体、二次電池、及びこれらの製造方法”

Japan Patent, 3495814（2004）

4. 川上総一郎，三品伸也，小林直哉

“電池用電極及び該電極を有するリチウム二次電池”

Japan Patent, 3495814（2003）

5. 川上総一郎，浅尾昌也

“リチウム二次電池の負極用電極材、該電極材を用いた電極構造体、該電極構造体を 用いたリチウム二次電池、及び該電極構造体及び該リチウム二次電池の製造方法”

Japan Patent, 3733292（2005）

104

6. 川上総一郎，浅尾昌也，小倉孝夫，都築英寿，小鈴武，小林直哉

“リチウム二次電池用の電極材料、該電極材料を有する電極構造体、該電極構造体を 有する二次電池、前記電極材料の製造方法、前記電極構造体の製造方法、及び前記二 次電池の製造方法”

Japan Patent, 4164342（2008）

7. 川上総一郎，浅尾昌也，小林直哉，小鈴武，木村浩直

“電極構造体及び二次電池”

Japan Patent, 4227581（2008）

8. 浅尾昌也，川上総一郎，小倉孝夫

“リチウム二次電池用の電極材料、該電極材料を有する電極構造体、該電極構造体を 有する二次電池”

Japan Patent, 4366222（2009）

9. 河村直也，川上総一郎

“リチウム二次電池”

Japan Patent, 4366101（2009）

10. 川上総一郎，浅尾昌也，鈴木伸幸，山田康博，小倉孝夫

“リチウム二次電池用の電極材料、該電極材料を有する電極構造体、及び該電極構造 体を有する二次電池”

Japan Patent, 4464173（2010）

11. 川上総一郎，浅尾昌也，小倉孝夫，都築英寿，小鈴武，小林直哉

“リチウム二次電池用の負極材料、負極構造体及び二次電池”

Japan Patent, 4898737（2012）

12. Soichiro Kawakami, Shinya Mishina, Naoya Kobayashi, Masaya Asao

“Lithium secondary cell with an alloyed metallic powder containing electrode”

U.S. Patent, 5795679 (1998)

13. Soichiro Kawakami, Naoya Kobayashi, Masaya Asao, Takeshi Kosuzu, Hironao Kimura

“Electrode structural body, rechargeable battery provided with said electrode structural body, and rechargeable battery”

U.S. Patent, 6432585 (2002)

14. Naoya Kobayashi, Soichiro Kawakami, Tomoya Yamamoto

105

“Lithium secondary battery and method of manufacturing the lithium secondary battery”

U.S. Patent, 6517974 (2003)

15. Naoya Kobayashi, Soichiro Kawakami, Tomoya Yamamoto

“Lithium secondary battery and method of manufacturing the lithium secondary battery”

U.S. Patent, 6569568 (2003)

16. Soichiro Kawakami, Shinya Mishina

“Electrode material for anode of rechargeable lithium battery, electrode structural body using said electrode material, rechargeable lithium battery using said electrode structural body, process for producing said electrode structural body, and process for producing said rechargeable lithium battery”

U.S. Patent, 6949312 (2005)

17. Soichiro Kawakami, Shinya Mishina, Naoya Kobayashi, Masaya Asao

“Rechargeable lithium battery”

U.S. Patent, 6051340 (2000) 18. Soichiro Kawakami, Masaya Asao

“Electrode material for anode of rechargeable lithium battery, electrode structural body using electrode material, rechargeable lithium battery using said electrode structural body, process for producing said electrode structural body, and process for producing said rechargeable lithium battery”

U.S. Patent, 6730434 (2004) 19. Soichiro Kawakami, Masaya Asao

“Electrode material for anode of rechargeable lithium battery, electrode structural body using said electrode material, rechargeable lithium battery using said electrode structural body, process for producing said electrode structural body, and process for producing said rechargeable lithium battery”

U.S. Patent, 6949312 (2005)

20. Takeshi Kosuzu, Soichiro Kawakami, Masaya Asao, Hidetoshi Tsuzuki, Takao Ogura, Naoya Kobayashi

“Electrode material for rechargeable lithium battery, electrode structural body comprising said electrode material, rechargeable lithium battery having said electrode structural body, process

106

for the production of said electrode structural body, and process for the production of said rechargeable lithium battery”

U.S. Patent, 7141187 (2006) 21. Soichiro Kawakami, Masaya Asao

“Electrode material for anode of rechargeable lithium battery, electrode structural body using said electrode material, rechargeable lithium battery using said electrode structural body, process for producing said electrode structural body, and process for producing said rechargeable lithium battery”

U.S. Patent, 7183018 (2007)

22. Takeshi Kosuzu, Soichiro Kawakami, Masaya Asao, Hidetoshi Tsuzuki, Takao Ogura, Naoya Kobayashi

“Electrode material for rechargeable lithium battery and electrode structural body comprising said electrode material”

U.S. Patent, 7316792 (2008)

23. Masaya Asao, Soichiro Kawakami, Takao Ogura

“Electrode material for lithium secondary battery, electrode structure comprising the electrode material and secondary battery comprising the electrode structure”

U.S. Patent, 7378041 (2008)

24. Masaya Asao, Soichiro Kawakami, Takao Ogura

“Electrode material for lithium secondary battery, electrode structure comprising the electrode material and secondary battery comprising the electrode structure”

U.S. Patent, 7425285 (2008) 25. Soichiro Kawakami, Masaya Asao

“Electrode material for anode of rechargeable lithium battery, electrode structural body using said electrode material, rechargeable lithium battery using said electrode structural body, process for producing said electrode structural body, and process for producing said rechargeable lithium battery”

U.S. Patent, 7534528 (2009)

26. Naoya Kawamura, Soichiro Kawakami

“Lithium secondary battery”

107 U.S. Patent, 7575830 (2009)

27. Soichiro Kawakami, Hidetoshi Tsuzuki, Toshiaki Aiba, Rie Ueno, Masatoshi Watanabe

“Powder material, electrode structure using the powder material, and energy storage device having the electrode structure”

U.S. Patent, 8080335 (2011)

28. Kawakami Soichiro, Kobayashi Naoya, Asao Masaya, Kosuzu Takeshi, Kimura Hironao

“Electrode structural body, rechargeable battery provided with said electrode structural body, and process for the production of said electrode structural body and said rechargeable battery”

EP Patent, 0855752 (2006)

29. Kobayashi Naoya, Kawakami Soichiro, Yamamoto Tomoya

“Lithium secondary battery and method of manufacturing the lithium secondary battery”

EP Patent, 0938147 (2006)

30. Kawakami Soichiro, Mishina Shinya, Kobayashi Naoya, Asao Masaya

“Rechargeable lithium battery”

EP Patent, 0690517 (2003) 31. Kawakami Soichiro, Asao Masaya

“Electrode material for negative pole of lithium secondary cell, electrode structure using said electrode material, lithium secondary cell using said electrode structure, and method for manufacturing said electrode structure and said lithium secondary cell”

EP Patent, 1033767 (2010) 32. Kawakami Soichiro, Asao Masaya

“Electrode material for negative pole of lithium secondary cell, electrode structure, and method for manufacturing said electrode structure and said lithium secondary cell”

EP Patent, 1039568 (2009)