Nec Corporation

Other

Tomoyuki Ohta

Jiro Iriyama

Masato Shirakata

Hajime Satoh

Junji Tabuchi

Tamaki Nakahashi

A rechargeable nonaqueous electrolyte secondary battery has a positive electrode which can be doped with lithium ions and de-doped thereof, a nonaqueous electrolyte solution and a negative electrode. The negative electrode active material is a carbon material including at least two component: (a) flake graphite particles; and (b) a non-flake graphite material whose surface is covered with amorphous carbon. This secondary battery has a high capacity and is excellent charging/discharging efficiency.

Nonaqueous electrolyte secondary cell, method for manufacturing the same, and carbonaceous material composition

An active material free part of a positive electrode is coated with an over-coat material, wherein the over-coat material has at least one of the following properties: suppression of heat transfer from the second part of the electrode to the separator; reduction of a heat transfer rate from the second part of the electrode to the separator; prevention of transfer of excess heat from the second part of the electrode to the separator; electrical isolation of the second part of the electrode from the separator; prevention of charges generated in the first active material from becoming concentrated in the second part of the electrode and discharged from the second part; and prevention of the separator from being melted by a current discharge from or into the second part of the electrode through the separator until the current discharge is shut down by a fuse function of the separator.

Explosion-resistant large capacitive lithium ion secondary battery

A nonaqueous electrolyte secondary battery includes a pair of an anode and a cathode, the anode being made of a transition metal lithium compound oxide capable of charging and discharging lithium ions; and a nonaqueous electrolyte having a supporting electrolyte, wherein the supporting electrolyte includes lithium-bis-penta-fluoroethylsulfonylimide (Li&lsqb;N(SO,C,F,),&rsqb;) and is free of other lithium salts.

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Tokyo, Japan

Tomoyuki Ohta