You should always clear the cache from your phone to run periodically, you could help to eliminate the performance issue on your phone.
Over time your phone get collected a unnecessary data , you can clear the data to free the space in your mobile to function smoothly.
How To Extend battery life in Mobile
1-Turn on adaptive brightness in your Mobile
2-Close the Apps that are running in background
3-Reduce the sleep time out
4-Turn off GPS running in Back
5-Don't overcharge the battery.