If you hire a battery scientist expecting them to run your pilot line, you’re going to have a bad time.
TLDR:
Battery roles are not interchangeable, even if the titles sound similar.
Job descriptions reveal what companies actually expect people to do.
Titles don’t build batteries. Skill sets do.
What Each Role Does
Battery Scientist
Core training: electrochemistry, materials science, fundamental mechanisms
They are trained to:
Discover, explain, and de-risk unknowns
Understand why a material behaves the way it does
Connect structure to performance and failure
Produce intellectual property, invent new materials from scratch
Solve problems that are purely scientific in nature
JDs Tend to Emphasize:
Materials synthesis & characterization
Structure–property relationships
CV, EIS, GITT, failure mechanisms
Technical reports, patents, publications
BBB translation:
Battery scientists reduce uncertainty. They do not reduce throughput risk.
Cell Engineer
Core training: process engineering, scale-up, manufacturability
They are trained to:
Design cells that can actually be built repeatedly
Translate lab results into real processes
Balance performance against cost, yield, and reliability
Own manufacturing yield
Run pilot lines
Debug production-scale process chaos
JDs Tend to Emphasize:
Cell design tradeoffs (loading, thickness, format)
Coating, calendering, formation, scale-up
Cross-functional work with manufacturing and quality
Translating performance into repeatable processes
BBB translation:
Cell engineers turn physics into something you can build twice.
Test Engineer
Core training: validation, data integrity, failure discovery
They are trained to:
Design test plans that catch real problems
Own cyclers, fixtures, and data pipelines
Tell you whether performance trends are real or noise
JDs Tend to Emphasize:
In large, mature companies:
Validation plans
Documentation, traceability, standards
Reliability, abuse testing, compliance
In early-stage startups:
Building test infrastructure from scratch
Debugging failures with incomplete context
Owning data sanity while everything else moves fast
Key insight:
The responsibilities change with stage.
The ownership does not.
BBB translation:
If no one owns your test data, your company is running on vibes.
The real failure mode isn’t hiring the “wrong” person.
It’s hiring the right person for the wrong problem and then being surprised when nothing works.
Early-stage battery companies fail when:
Scientists are asked to fix yield
Engineers are asked to invent physics
Test engineers are treated like “support” instead of owners
That’s how you end up with:
Gorgeous plots nobody trusts
Pilot lines that only work once
Performance claims built on unowned data
Battery teams don’t fail because the people aren’t smart.
They fail because leadership doesn’t understand role boundaries.
Titles don’t build batteries.
People do.
Some Resources We Love:
Aka: the job descriptions that inspired this post
These JDs are excellent examples of how companies signal what they actually expect someone to own, regardless of title.