Solid-state battery coatings need fast lithium-ion transport. The standard approach: optimize chemistry, engineer grain boundaries, anneal at precise temperatures. Kumar et al. (arXiv:2603.12898) take a different route. They bombard lithium borate cathode coatings with thermal neutrons from a research reactor.
The neutrons selectively transmute boron-10 and lithium-6 isotopes, knocking atoms out of their lattice sites. This creates vacancies — empty spots that ions can hop through. Within grains, conductivity rises about 20%. But at grain boundaries, where transport is usually bottlenecked, conductivity jumps more than 80%.
The mechanism has two parts working in concert. The transmutation punches vacancies into the crystal lattice without destroying long-range order — targeted damage, not demolition. Simultaneously, the nuclear reactions produce gamma photons that release electrons, which partially neutralize the positively charged oxygen vacancies accumulating at grain boundaries. The space charge that normally repels lithium ions gets screened.
The counterintuitive part: radiation damage is usually the enemy of ordered materials. Here it's precisely the kind of damage that helps, introduced at precisely the scale that matters. The neutrons are thermal — slow enough to be captured by specific isotopes rather than smashing through the lattice indiscriminately. The destruction is selective, and selective destruction of barriers is construction of pathways.
This is engineering by subtraction. You don't build a better conductor; you remove the obstacles in an existing one. The material already had the crystal structure it needed. What it lacked were the vacancies to make that structure permeable.