When you follow the main questline for Shattered Space and get to the quest "Promised, broken" you will then meet in the city a guy named Ekris Kaisir who will then tell you about Vortex Grenades, after this dialogue you can then craft 5 different Vortex Grenades in any Industrial Workbench.
You will then need these items to craft the five different vortex grenades:
Vortex Grenade - Binding
1 Dark Vortex Cyst
1 Vortex Shard
Vortex Grenade - Charged
1 Glowing Vortex Cyst
1 Vortex Shard
Vortex Grenade - Lure
1 Vortex Cyst
1 Dark Vortex Cyst
1 Vortex Shard
Vortex Grenade - Phasing
1 Vortex Cyst
1 Glowing Vortex Cyst
1 Vortex Shard
Vortex Grenade - Unstable
1 Vortex Shard
1 Vortex Cyst
All in all you'll need:
5 Vortex Shards
3 Vortex Cysts
2 Dark Vortex Cysts
2 Glowing Vortex Cysts
To get these different Vortex Cysts you need to progress the story (or explore the planet) and defeat different types of Vortex Horrors (kill 25 of those for another achievement), these Vortex Horrors can drop one of the three different Cysts you need to craft the Vortex Grenades.
Vortex Shards drop from the Vortex entities/phantoms that you meet in the Oracle and in the new planet "Va'ruun'kai".
The Vortex Horrors glow just like the entities/phantoms, but instead of human entities they are different monsters/beasts like for example a huge Crab entity (usually called "Hunting Rocky Bonecrest" when you find the in the wild around the planet).
These Vortex Horrors can have names like "Vile Vortex Horror" or "Dim Vortex Spawn".
Kill these Vortex Horrors to get Vortex Cysts like Dark Vortex Cyst, Glowing Vortex Cyst and Vortex Cyst to get enough to craft all 5 Vortex Grenades on a Industrial Workbench in an outpost or in your ship if you have put one there.