I can't imagine not having a mobile phone. When the DC were younger, I remember having to get DH to pick them from the childminder or after school club if I was stuck in traffic.
I think the only time he'll get one, is if/when something serious happens to you or your DC and he was uncontactable. Or if he runs into trouble himself, that would have been avoided if he had a mobile phone.
Apart from that, I would suggest you try and organise your supplies , so you don't have to ask him for anything on his way home.
Can I ask if he ever calls you on your mobile for things?
There was a school mum who didnt have a mobile and she'd go to the school office in the morning, telling them her days agenda and who's house to contact her in, just in case the DC were ill. So annoying.
If it was my DH, I'd create a number of scenarios over a period of time that he misses out on and that he wouldn't have missed out, if he had a mobile phone.
For example ...
"Someone at work had two tickets going cheap to see [insert his football team] playing, but I couldn't get hold of you to see if you were interested. Never mind, they're gone now".
My DH would be getting a phone the next day.