Appeal 2007- 3662
Application 09/997,604
properties of the positive electrode of the secondary lithium batteries
(Manev, col. 1, ll. 40-47). Manev discusses the properties affected by the
mean particle size (Manev, col. 1, ll. 43 to col. 2, l. 10), and provides
guidance as to how to obtain desired particle size by selecting appropriate
heating temperatures, heating duration, and the size of manganese compound
starting particles (Manev, col. 4, l. 30 to col. 5, l. 33). Manev discloses that
a mean particle size of 10-15 µm provides good properties (Manev, col. 5, ll.
24-33). Particles of such size necessarily have faces with lengths of 1 µm or
more.
Okada, Zhong ‘104, and Manev each describe how to obtain spinel
crystals by heating, in one or two stages, a mixture of salts and oxides of Li,
Mn, and any other metal to be included in an oxidizing atmosphere (Okada
¶¶ 0075 and 78 (heat to 500°C or lower then heat to 500-850°C, for,
preferably, 10 or more hours); Zhong ‘104, col. 6, ll. 3-6 (750-950°C one or
more times); Manev, col. 4, ll. 30-54 (400-600°C for at least 12 hours then
700-900°C for at least 10 hours). The temperatures and times of the prior art
are in substantially the same range as Appellants’ temperatures and times
(Specification 11:5-10 (700-900°C for 5-50 hours)). But most importantly,
all the references perform the heating step specifically to obtain a spinel
structure, i.e., crystals of octahedral shape. One of ordinary skill in the art
would have conducted the process in order to get the desired crystals.
We also agree with the Examiner that it is reasonable to conclude that
the primary particles formed in the Inventive Example 3 of Zhong ‘104 (col.
9, ll. 32-37) would have particles with face lengths of 1 µm or more as
claimed. While Appellants contend that not all temperatures and times will
result in the claimed morphology (Br. 14-15), Inventive Example 3 of Zhong
8
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