Battery, method of charging and discharging the battery and charge-discharge control device for the battery

Abstract

Provided is a battery capable of improving cycle characteristics through reducing a structural fracture according to charge and discharge of an anode and a reaction of the with an electrolyte. An anode active material layer includes at least one kind selected from the group consisting of a simple substance and alloys of Si capable of forming an alloy with Li. A cathode and an anode are formed so that the molar ratio Li/Si in the anode at the time of charge is 4.0 or the potential of the anode vs. Li is 0.04 V or more through adjusting, for example, a ratio between a cathode active material and an anode active material. Moreover, the cathode and the anode are formed so that the molar ratio Li/Si in the anode at the time of discharge is 0.4 or more, or the potential of the anode vs. Li is 1.4 V or less.

1 . A battery, comprising: 
 an anode including silicon (Si) as an element and being capable of inserting and extracting lithium (Li);    a cathode being capable of inserting and extracting lithium; and    an electrolyte,    wherein a molar ratio of lithium atoms to silicon atoms (Li/Si) in the anode is 4.0 or less.    
   
   
       2 . A battery according to  claim 1 , wherein 
 a molar ratio of lithium atoms to silicon atoms (Li/Si) in the anode is 0.4 or more.    
   
   
       3 . A battery according to  claim 1 , wherein 
 the anode includes an anode current collector and an anode active material layer being disposed on the anode current collector, including silicon as an element, and being alloyed with the anode current collector at at least a part of an interface with the anode current collector.    
   
   
       4 . A battery according to  claim 1 , wherein 
 the anode includes an anode current collector and an anode active material layer being formed on the anode current collector by at least one method selected from the group consisting of a vapor-phase deposition method, a liquid-phase deposition method and a sintering method, and including silicon as an element.    
   
   
       5 . A battery according to  claim 1 , wherein 
 the electrolyte includes at least one kind selected from the group consisting of a cyclic carbonate having an unsaturated bond and a carbonate derivative containing a halogen atom.    
   
   
       6 . A battery, comprising: 
 an anode including silicon (Si) as an element and being capable of inserting and extracting lithium (Li);    a cathode being capable of inserting and extracting lithium; and    an electrolyte,    wherein a potential of the anode vs. lithium metal as a reference po tential is 0.04 V or more.    
   
   
       7 . A battery according to  claim 6 , wherein 
 a potential of the anode vs. lithium metal as a reference potential is 1.4 V or less.    
   
   
       8 . A battery according to  claim 6 , wherein 
 the anode includes an anode current collector and an anode active material layer being disposed on the anode current collector, including silicon as an element, and being alloyed with the anode current collector at at least a part of an interface with the anode current collector.    
   
   
       9 . A battery according to  claim 6 , wherein 
 the anode includes an anode current collector and an anode active material layer being formed on the anode current collector by at least one method selected from the group consisting of a vapor-phase deposition method, a liquid-phase deposition method and a sintering method, and including silicon as an element.    
   
   
       10 . A battery according to  claim 6 , wherein 
 the electrolyte includes at least one kind selected from the group consisting of a cyclic carbonate having an unsaturated bond and a carbonate derivative containing a halogen atom.    
   
   
       11 . A method of charging and discharging a battery, the battery comprising an anode which includes silicon (Si) as an element and is capable of inserting and extracting lithium (Li), 
 wherein at the time of charge, a molar ratio of lithium atoms to silicon atoms (Li/Si) in the anode is 4.0 or less.    
   
   
       12 . A method of charging and discharging a battery according to  claim 11 , wherein 
 at the time of discharge, a molar ratio of lithium atoms to silicon atoms (Li/Si) in the anode is 0.4 or more.    
   
   
       13 . A method of charging and discharging a battery, the battery comprising an anode which includes silicon (Si) as an element and is capable of inserting and extracting lithium (Li), 
 wherein a potential of the anode vs. lithium metal as a reference potential at the time of charge is 0.04 V or more.    
   
   
       14 . A method of charging and discharging a battery according to  claim 13 , wherein 
 a potential of the anode vs. lithium metal as a reference potential at the time of discharge is 1.4 V or less.    
   
   
       15 . A charge-discharge control device for a battery, the battery comprising an anode which includes silicon (Si) as an element and is capable of inserting and extracting lithium (Li), the charge-discharge control device comprising. 
 a charge control portion for controlling a molar ratio of lithium atoms to silicon atoms (Li/Si) in the anode at the time of charge to 4.0 or less.    
   
   
       16 . A charge-discharge control device for a battery according to  claim 15 , further comprising: 
 a discharge control portion for controlling a molar ratio of lithium atoms to silicon atoms (Li/Si) in the anode at the time of discharge to 0.4 or more.    
   
   
       17 . A charge-discharge control device for a battery, the battery comprising an anode which includes silicon as an element and is capable of inserting and extracting lithium (Li), the charge-discharge control device comprising: 
 a charge control portion for controlling a potential of the anode vs. lithium metal as a reference potential at the time of charge to 0.04 V or more.    
   
   
       18 . A charge-discharge control device for a battery according to  claim 17 , further comprising: 
 a discharge control portion for controlling a potential of the anode vs. lithium metal as a reference potential at the time of discharge to 1.4 V or less.