Motivation influences learning outcomes. Being aware of the reward from acquiring new skills and studying demanding topics makes it easier to put time and effort in the process and keep delivering on challenging tasks.
To keep your own and your team motivation high consider the practices that will make you all more aware of your development and the gains from making the effort to develop new skills.
What are the most challenging tasks you are delivering on and how will they improve your skills?
What kind of practices you could create to make your team reflect on their own development regularly?