Negative electrode material and battery using the same
View Patent ↗A negative electrode material and a battery which have an excellent cycle characteristic as well as a high capacity are provided. A positive electrode housed in an exterior can and a negative electrode housed in an exterior cup are laminated with a separator therebetween. An electrolytic solution of lithium salt dissolved in a solvent is poured into the inside of both the exterior can and the exterior cup. The negative electrode contains Mg 2−x MII x MI. MI expresses a first element such as Si, Sn, Ge, Pb, or the like. MII expresses a second element which is a metallic element, preferably Mn, Cu, Zn, or the like except both Mg and the first element. X is preferably in the range of 0.1≦x≦1.9. Substituting part of Mg by the second element MII can produce the distortion of the crystal structure, ease distortion accompanying the occluding/releasing lithium, and improve the charge and discharge efficiency and the cycle characteristic.
1. A negative electrode for a battery comprising a compound, the compound consisting essentially of:
(a) magnesium (Mg),
(b) a first element of at least one element selected from the group consisting of silicon (Si), tin (Sn), germanium (Ge), and lead (Pb), and
(c) a second element of at least one element selected from the group consisting of manganese (Mn), copper (Cu), and zinc (Zn),
wherein,
the ratio (Mg+M 2 ):M 1 is equal to 2:1, wherein Mg is the moles of magnesium, M 2 is the moles of the second element, and M 1 is the moles of the first element, and
the negative electrode further comprises a carbonaceous material.
2. A negative electrode according to claim 1 , wherein the composition ratio of the second element to magnesium ((the second element)/magnesium)) is in a range of 0.1/1.9 to 1.9/0.1 inclusive in mol ratio.
3. A negative electrode according to claim 2 , wherein the carbonaceous material contains at least one element selected from the group consisting of a non-graphitizing carbon material, a graphitizing carbon material, and graphite.
4. A battery comprising an electrolyte with a positive electrode and a negative electrode,
wherein
the negative electrode contains a compound, the compound consisting essentially of magnesium (Mg), a first element of at least one element selected from the group consisting of silicon (Si), tin (Sn), germanium (Ge), and lead (Pb), and a second element of at least one element selected from the group consisting of manganese (Mn), copper (Cu), and zinc (Zn),
a ratio (Mg+M 2 ):M 1 is equal to 2:1, Mg being the moles of magnesium, M 2 being the moles of the second element, and M 1 being the moles of the first element, and
the negative electrode further comprises a carbonaceous material.
5. A battery according to claim 4 , wherein the composition of the second element to magnesium ((the second element)/(magnesium)) is in a range of 0.1/1.9 to 1.9/0.1 inclusive in mole ratio.
6. A battery according to claim 4 , wherein the carbonaceous material contains at least one element selected from the group consisting of a non-graphitizing carbon material, a graphitizing carbon material, and graphite.