EV Charging - Can you claim tax relief on difference between advisory electricity rate and cost

I have a company provided EV - current advisory electricity rate is 9p per mile for business use. I am fixed at home until March 2024 and the rate I am paying just about covers that for local use, however I have to travel journeys of 650 miles each way bi weekly and journeys in excess of the cars range weekly for the company - I try to find the cheapest chargers I can, but the 9p per mile is far short of the actual cost. Is there a way of claiming back the difference for business use? Last week, I ended up using a charger that was 44p KWH, my car does 3.3 miles kWh, on a 1300 mile round trip, I am heavily subsidising from my own pocket - thanks

Hi,

From 31 March 2023, the advisory electricity rate for fully electric cars rose from 8 pence to 9 pence per mile. The advisory electricity rate for fully electric cars is the value of the Annual Equivalent Rate, calculated by taking the cost of electricity per mile for each model provided by the DFT and electricity price data from BEIS and ONS. Based on company car sales data across the last 3 years, a weighted average value of the electrical costs per mile for a fully electric car is then calculated. 
The guidance on advisory rates state that if your employer pays a rate higher than the advisory rate, the difference is a benefit in kind and is subject to tax and NIC. 

Advisory fuel rates

Thank you.