There's nothing wrong with an NTC thermistor, it's as 'proper' as anything. Silicon sensors maybe be better or worse than in some regards. As may RTDs or thermocouples or other more exotic sensors.
As well as accuracy and stability (which are usually quite good for an NTC thermistor, at least over a modest temperature range) consider how well you can couple the sensor to what you are trying to measure. Most temperature sensors do an excellent job of measuring their own temperature, however that reading may lag behind (due to poor heat transfer and large heat capacity- especially an issue with still air temperature measurements) or have a large offset to what you are actually intending to measure due to heat loss down the leads, self-heating etc.
Thermistors are cheaply available with very tight tolerance thanks to consumer mass markets. Something like an LM35 or LM335 is accurate to around +/-1°C. A thermistor could be more like +/-0.2°C - 5x better for maybe 1/20 the cost.
For a battery temperature measurement, something like a 10kΩ NTC thermistor is an appropriate solution and is the standard approach. It doesn't need to be a 1% type but you can use one if you like. If you'd prefer (for some reason) to avoid any analog electronics and care little about cost effectiveness, monolithic digital output sensors are available.