ANALYSIS-Bolivia holds key to lithium, the battery car metal

* Lithium demand to outstrip other battery metals

* Mining Bolivia's lithium wealth won't be easy

* Electric cars to fuel the increase in lithium

By Michael Taylor

LONDON, April 14 (Reuters) - Minor metal lithium is set to charge ahead to become the top material for batteries and vital for electric transport, but supplying any spike in demand could be fraught with difficulties.

Bolivia, a poor but resource-rich country governed for the past three years by leftist Evo Morales, has about 50 percent of the world's lithium deposits at about 5.4 million tonnes.

But Morales has an uneasy relationship with the United States and big business -- having already nationalized energy, mining and telecommunications companies.

"It's not open to investment," said Charles Kernot, a mining analyst at Evolution Securities. "If you can't get agreement from the Bolivian authorities, then no major mining company would be able to get in and develop the projects."