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US 8,574,764 B2Granted
Negative active material including silicon active particles surrounded by copper, aluminum and tin metal matrix and rechargeable lithium battery including the same
AssigneeSamsung SDI Co., Ltd.
InventorsMin-Seok Sung, Sang-Jin Kim, Goo-Jin Jeong, Yong-Mook Kang
Life of this patent
Estimating the term…
Abstract
A negative active material for a rechargeable lithium battery includes Si active particles, and a 3-component to 7-component metal matrix that surrounds the active fine particles without reacting therewith. The negative active material shows high capacity and improved cycle-life characteristics.
Claims9
A negative active material for a rechargeable lithium battery, comprising:
- Si active particles in an amount of 30 to 70 wt % based on the weight of the negative active material;
- and
- a metal matrix being a three component metal matrix surrounding the Si active particles without chemically reacting with the Si active particles, the metal matrix comprising Cu, Al, and an additive metal, the Si active particles and the metal matrix being present in an alloy represented by Formula 1:
- xSi-y(aCu-bAl)-zX (1),
- Formula 1 having limitations including:
- x ranges from 30 to 70 wt %;
- y ranges from 30 to less than 70 w-t %;
- z is more than 0 wt % and 30 wt % or less;
- x+y+z is 100 wt %, and y+z is 30 to 70 wt %;
- when a+b is 100 wt %, a weight ratio of a and b ranges from 70:30 to 95:5;
- and
- X is the additive metal forming a solid-solution alloy with Cu and Al and is Sn.
9 more elements
A rechargeable lithium battery comprising:
- a negative electrode comprising a negative active material, the negative active material comprising Si active particles in an amount of 30 to 70 wt % based on the weight of the negative active material and a three component metal matrix surrounding the Si active particles without reacting with the Si active particles, the three component metal matrix comprising Cu, Al, and an additive metal, the Si active particles and the metal matrix being present in an alloy represented by Formula 1:
- xSi-y(aCu-bAl)-zX (1),
- Formula 1 having limitations including:
- x ranges from 30 to 70 wt %;
- y ranges from 30 to less than 70 w-t %;
- z is more than 0 wt % and 30 wt % or less;
- x+y+z is 100 wt %, and y+z is 30 to 70 wt %;
- when a+b is 100 wt %, a weight ratio of a and b ranges from 70:30 to 95:5;
- and
- X is Sn;
- a positive electrode including a positive active material capable of reversely intercalating/deintercalating lithium ions;
- and
- an electrolyte between the negative electrode and the positive electrode.
10 more elements
A method of preparing a negative active material, comprising:
- mixing Si active particles and three kinds of metals to obtain a mixture, the three kinds of metals comprising Cu, Al, and Sn;
- melting the mixture;
- and
- quenching the molten mixture to prepare the negative active material comprising a metal matrix comprised of said three kinds of metals and the Si active particles surrounded by the metal matrix, an amount of the Si active particles ranging from 30 to 70 wt % based on the weight of the negative active material, the Si active particles and the metal matrix being present in an alloy represented by Formula 1:
- xSi-y(aCu-bAl)-zX (1),
- Formula 1 having limitations including:
- x ranges from 30 to 70 wt %;
- y ranges from 30 to less than 70 w-t %;
- z is more than 0 wt % and 30 wt % or less;
- x+y+z is 100 wt %, and y+z is 30 to 70 wt %;
- when a+b is 100 wt %, a weight ratio of a and b ranges from 70:30 to 95:5;
- and
- X is Sn.
10 more elements
Dependencies are inferred from the claim text.