Just bolting it back on without welding up that ripped mounting hole wouldn't be advisable.
From having removed a pack on a North American car, that bracket does not look familiar, but with a big gusset down the middle, it definitely appears to be structural.
2012 i-SE "MR BEAN" 70,000 miles
i-ES traded at 21,648 miles
2000 Honda Odyssey
1987 F250 Diesel
1983 Grumman Kurbwatt,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet