So, far, it seems there are extended batteries out that are compatible with GB/TI8287-2000, but the design of the battery, if the pictures are accurate, would indicate they are physically incompatible. The main problem is that any site I go to has the same picture for displaying the battery.
2600Mah Battery
1200Mah Battery
An alternate reference # seem to be CS-ET280SL
The GB/T18287-2000 or CS-ET280SL batteries are typically found in these devices:
Dallab DP900 PDA
Dallab xg 500p PDA
Lenovo Lenove ET280 PDA
If I had to guess, this battery seems like a close alternative. This battery is for the Ipod Photo.
PMPAIPHOTO
Of course, all this information is gleaned from web searches, so all the information could be inaccurate.