Possible? Yes, but I'm not sure if my answer is what you are asking about.
When people normally speak about fusion energy, they are referring to fusing small nuclei, such as hydrogen, deuterium or tritium. Any nuclei which fuse to create something smaller than iron will release energy when fused. If you create something the size of iron or larger, it requires energy to do this. So, in a sense, stars that create elements heavier than iron (like supernovae) are storing energy using fusion.
You could fuse two small nuclei to make a larger nucleus that decays later. Fusing deuterium to make tritium (a beta emitter) would be an example. To make it useful, you would probably want to generate an isotope which had a natural decay rate which was appropriate for your storage system. It is generally going to cost more energy to make these than you will get out, and if you can already fuse small nuclei, then fusing those directly is a better energy source.
I suppose in theory one could use energy to break apart small nuclei, then fuse them later. This would qualify. I'm not sure what motivates your question. The practical answer is that light nuclei are already widely available, so if you can fuse them, then using them as a fuel is the most efficient way to have an energy storage system.
There was a bit of research into ways to release energy from nuclear isomers (Hf 178m2) a few years ago, but it appears to have not panned out. If this had worked out, one could make a nuclear isomer with fusion and do this.
When people normally speak about fusion energy, they are referring to fusing small nuclei, such as hydrogen, deuterium or tritium. Any nuclei which fuse to create something smaller than iron will release energy when fused. If you create something the size of iron or larger, it requires energy to do this. So, in a sense, stars that create elements heavier than iron (like supernovae) are storing energy using fusion.
You could fuse two small nuclei to make a larger nucleus that decays later. Fusing deuterium to make tritium (a beta emitter) would be an example. To make it useful, you would probably want to generate an isotope which had a natural decay rate which was appropriate for your storage system. It is generally going to cost more energy to make these than you will get out, and if you can already fuse small nuclei, then fusing those directly is a better energy source.
I suppose in theory one could use energy to break apart small nuclei, then fuse them later. This would qualify. I'm not sure what motivates your question. The practical answer is that light nuclei are already widely available, so if you can fuse them, then using them as a fuel is the most efficient way to have an energy storage system.
There was a bit of research into ways to release energy from nuclear isomers (Hf 178m2) a few years ago, but it appears to have not panned out. If this had worked out, one could make a nuclear isomer with fusion and do this.