Add ref

joss/paper.bib

@@ -217,3 +217,18 @@ @Article{Kirk:2022
   url     = {https://iopscience.iop.org/article/10.1149/1945-7111/acada7},
 }
 
+@Article{Couto:2023,
+  author    = {Couto, Luis D. and Charkhgard, Mohammad and Karaman, Berke and Job, Nathalie and Kinnaert, Michel},
+  journal   = {Energy},
+  title     = {Lithium-ion battery design optimization based on a dimensionless reduced-order electrochemical model},
+  year      = {2023},
+  issn      = {03605442},
+  number    = {PE},
+  pages     = {125966},
+  volume    = {263},
+  annote    = {Read and made notes 14/9/23.},
+  doi       = {10.1016/j.energy.2022.125966},
+  publisher = {Elsevier Ltd},
+  url       = {https://doi.org/10.1016/j.energy.2022.125966},
+}
+

joss/paper.md

@@ -169,7 +169,7 @@ in which $L : \mathbf{\theta} \mapsto [0,\infty)$ is a cost function that quanti
 of the design and $\mathbf{\Omega}$ is the set of allowable parameter values.
 
 As an example, let us consider the target of maximising gravimetric energy density subject to
-constraints on the geometric electrode parameters.
+constraints on the geometric electrode parameters [@Couto:2023].
 
 # Acknowledgements