Positive electrode material and battery using the same
View Patent ↗The invention provides a positive electrode material and a battery using the same which can achieve a higher discharge voltage and which can obtain excellent charge-and-discharge properties, without reducing the capacity. A positive electrode ( 12 ) and a negative electrode ( 14 ) are configured through a separator ( 15 ) in between. The positive electrode ( 12 ) contains a compound expressed by a general formula Li 1+x Mn y Fe z PO 4 (wherein x, y and z are values within ranges of 0<x<0.1, 0.5<y<0.95, and 0.9<y+z≦1, respectively). According to the compound, the higher discharge voltage can be obtained due to Mn, the Jahn Teller effect of Mn 3+ can be attenuated and furthermore distortion of the crystal structure and the reduction of the capacity can be inhibited due to Fe and the excess Li.
1. A positive electrode material containing a an olivine compound having excess lithium, the olivine compound being expressed by a general formula Li 1+x Mn y Fe z PO 4 , ( wherein x, y, and z are values within the ranges of 0<x<0.1, 0.5<y<0.95, and 0.9<y+z≦1 0.9<y+z<1, respectively), and the excess lithium provides higher discharge capacity in a battery.
2. A positive electrode material according to claim 1 , wherein the compound contains one having a particle having a diameter of 10 μm or less and the Brunauer-Emmet-Teller specific surface area thereof is 0.5 m 2 /g or more.
3. A battery comprising an electrolyte as well as a positive electrode and a negative electrode, wherein (a) the positive electrode contains a compound containing excess lithium and expressed by a general formula Li 1+x Mn y Fe z PO 4 (wherein,(b) x, y, and z are values within the ranges of 0<x≦0.1, 0.5<y<0.95, and 0.9<y+z<1, respectively), and (c) the excess lithium provides higher discharge capacity.
4. A battery according to claim 3 , wherein the positive electrode further comprises furthermore a conductive agent and a binder.
5. A battery according to claim 3 , wherein the negative electrode is constituted to contain one, two or more materials contains at least one material selected from the group consisting of lithium metals, lithium alloys, and materials a material capable of insertion and extraction of lithium.
6. A battery according to claim 5 , wherein the materials material capable of insertion and extraction of lithium is constituted to contain one, two or more materials contains at least one material selected from the group consisting of carbonaceous materials, metal compounds, silicon, silicon compounds, and conductive polymers.
7. A battery according to claim 3 , wherein the electrolyte is constituted to contain one, two or more materials contains at least one material selected from the group consisting of LiPF 6 , LiClO 4 , LiAsF 6 , LiBF 4 , LiCF 3 SO 3 , and LiN(CF 3 SO 2 ) 2 .